Building python38Packages.sh works locally but fails on nixbuild

[yajo]

I'm trying to diagnose a weird issue I'm having with nixbuild.

This command builds the derivation from the title remotely:

nix build nixpkgs/35130d4b4f0b8c50ed2aceb909a538c66c91d4a0#legacyPackages.x86_64-linux.python38Packages.sh --store 'ssh-ng://eu.nixbuild.net?ssh-key=/etc/ssh/ssh_host_ed25519_key' --eval-store auto -L

As you can see in the logs below, pytest fails:

warning: error: unable to download 'https://channels.nixos.org/flake-registry.json': Problem with the SSL CA cert (path? access rights?) (77); using cached version
python3.8-sh> Sourcing python-remove-tests-dir-hook
python3.8-sh> Sourcing python-catch-conflicts-hook.sh
python3.8-sh> Sourcing python-remove-bin-bytecode-hook.sh
python3.8-sh> Sourcing pip-build-hook
python3.8-sh> Using pipBuildPhase
python3.8-sh> Using pipShellHook
python3.8-sh> Sourcing pip-install-hook
python3.8-sh> Using pipInstallPhase
python3.8-sh> Sourcing python-imports-check-hook.sh
python3.8-sh> Using pythonImportsCheckPhase
python3.8-sh> Sourcing python-namespaces-hook
python3.8-sh> Sourcing python-catch-conflicts-hook.sh
python3.8-sh> Sourcing pytest-check-hook
python3.8-sh> Using pytestCheckPhase
python3.8-sh> unpacking sources
python3.8-sh> unpacking source archive /nix/store/v6hbjcc5ay3694bg19zjbhrn00f7k2rj-source
python3.8-sh> source root is source
python3.8-sh> setting SOURCE_DATE_EPOCH to timestamp 315619200 of file source/tox.ini
python3.8-sh> patching sources
python3.8-sh> configuring
python3.8-sh> no configure script, doing nothing
python3.8-sh> building
python3.8-sh> Executing pipBuildPhase
python3.8-sh> Creating a wheel...
python3.8-sh> WARNING: The directory '/homeless-shelter/.cache/pip' or its parent directory is not owned or is not writable by the current user. The cache has been disabled. Check the permissions and owner of that directory. If executing pip with sudo, you should use sudo's -H flag.
python3.8-sh> Processing /build/source
python3.8-sh>   Running command Preparing metadata (pyproject.toml)
python3.8-sh>   Preparing metadata (pyproject.toml) ... done
python3.8-sh> Building wheels for collected packages: sh
python3.8-sh>   Running command Building wheel for sh (pyproject.toml)
python3.8-sh>   Building wheel for sh (pyproject.toml) ... done
python3.8-sh>   Created wheel for sh: filename=sh-2.0.2-py3-none-any.whl size=38306 sha256=a8999ec9f4a529fcdabf23c8f1c1c3601214e1321ea6e315e1e5de16518f3b68
python3.8-sh>   Stored in directory: /build/pip-ephem-wheel-cache-d4qdmjb4/wheels/e1/fb/ff/3c7bf8327fe7b38e0848fbd084e404c8a61b776977c550714b
python3.8-sh> Successfully built sh
python3.8-sh> Finished creating a wheel...
python3.8-sh> Finished executing pipBuildPhase
python3.8-sh> installing
python3.8-sh> Executing pipInstallPhase
python3.8-sh> /build/source/dist /build/source
python3.8-sh> Processing ./sh-2.0.2-py3-none-any.whl
python3.8-sh> Installing collected packages: sh
python3.8-sh> Successfully installed sh-2.0.2
python3.8-sh> /build/source
python3.8-sh> Finished executing pipInstallPhase
python3.8-sh> pythonOutputDistPhase
python3.8-sh> Executing pythonOutputDistPhase
python3.8-sh> Finished executing pythonOutputDistPhase
python3.8-sh> post-installation fixup
python3.8-sh> shrinking RPATHs of ELF executables and libraries in /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2
python3.8-sh> checking for references to /build/ in /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2...
python3.8-sh> patching script interpreter paths in /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2
python3.8-sh> stripping (with command strip and flags -S -p) in  /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2/lib
python3.8-sh> shrinking RPATHs of ELF executables and libraries in /nix/store/w9cvl1gnyyqp18wybpajc5sz2cv85b96-python3.8-sh-2.0.2-dist
python3.8-sh> checking for references to /build/ in /nix/store/w9cvl1gnyyqp18wybpajc5sz2cv85b96-python3.8-sh-2.0.2-dist...
python3.8-sh> patching script interpreter paths in /nix/store/w9cvl1gnyyqp18wybpajc5sz2cv85b96-python3.8-sh-2.0.2-dist
python3.8-sh> Executing pythonRemoveTestsDir
python3.8-sh> Finished executing pythonRemoveTestsDir
python3.8-sh> running install tests
python3.8-sh> no Makefile or custom installCheckPhase, doing nothing
python3.8-sh> pythonCatchConflictsPhase
python3.8-sh> pythonRemoveBinBytecodePhase
python3.8-sh> pythonImportsCheckPhase
python3.8-sh> Executing pythonImportsCheckPhase
python3.8-sh> pytestCheckPhase
python3.8-sh> Executing pytestCheckPhase
python3.8-sh> ============================= test session starts ==============================
python3.8-sh> platform linux -- Python 3.8.17, pytest-7.2.1, pluggy-1.0.0
python3.8-sh> rootdir: /build/source
python3.8-sh> collected 178 items / 4 deselected / 174 selected
python3.8-sh> tests/test.py ...................................................s...... [ 33%]
python3.8-sh> ................................................F....................... [ 74%]
python3.8-sh> ............................................                             [100%]
python3.8-sh> =================================== FAILURES ===================================
python3.8-sh> _____________________ FunctionalTests.test_general_signal ______________________
python3.8-sh> self = <tests.test.FunctionalTests testMethod=test_general_signal>
python3.8-sh>         def test_general_signal(self):
python3.8-sh>             from signal import SIGINT
python3.8-sh>             py = create_tmp_test(
python3.8-sh>                 """
python3.8-sh>     import sys
python3.8-sh>     import os
python3.8-sh>     import time
python3.8-sh>     import signal
python3.8-sh>     i = 0
python3.8-sh>     def sig_handler(sig, frame):
python3.8-sh>         global i
python3.8-sh>         i = 42
python3.8-sh>     signal.signal(signal.SIGINT, sig_handler)
python3.8-sh>     for _ in range(6):
python3.8-sh>         print(i)
python3.8-sh>         i += 1
python3.8-sh>         sys.stdout.flush()
python3.8-sh>         time.sleep(1)
python3.8-sh>     """
python3.8-sh>             )
python3.8-sh>             stdout = []
python3.8-sh>             def agg(line, stdin, process):
python3.8-sh>                 line = line.strip()
python3.8-sh>                 stdout.append(line)
python3.8-sh>                 if line == "3":
python3.8-sh>                     process.signal(SIGINT)
python3.8-sh>                     return True
python3.8-sh>             p = python(py.name, _out=agg, _tee=True)
python3.8-sh>             p.wait()
python3.8-sh>             self.assertEqual(p.process.exit_code, 0)
python3.8-sh> >           self.assertEqual(str(p), "0\n1\n2\n3\n42\n43\n")
python3.8-sh> E           AssertionError: '0\n1\n2\n3\n43\n44\n' != '0\n1\n2\n3\n42\n43\n'
python3.8-sh> E             0
python3.8-sh> E             1
python3.8-sh> E             2
python3.8-sh> E             3
python3.8-sh> E           + 42
python3.8-sh> E             43
python3.8-sh> E           - 44
python3.8-sh> tests/test.py:1672: AssertionError
python3.8-sh> =============================== warnings summary ===============================
python3.8-sh> tests/test.py::FunctionalTests::test_unchecked_pipeline_failure
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 176
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.ErrorReturnCode_2:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmpq8ixpuiy
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_fg_alternative
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread STDIN thread for pid 230
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2606, in input_thread
python3.8-sh>       done = stdin.write()
python3.8-sh>     File "/build/source/sh.py", line 2919, in write
python3.8-sh>       chunk = self.get_chunk()
python3.8-sh>     File "/build/source/sh.py", line 2860, in fn
python3.8-sh>       chunk = stdin.read(bufsize)
python3.8-sh>     File "/nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/capture.py", line 192, in read
python3.8-sh>       raise OSError(
python3.8-sh>   OSError: pytest: reading from stdin while output is captured!  Consider using `-s`.
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_unchecked_producer_failure
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 331
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.ErrorReturnCode_2:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmpdfgj178a
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_exit_code_with_hasattr
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 417
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.ErrorReturnCode_3:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmp7gido342
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_done_cb_exc
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 574
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.ErrorReturnCode_1:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmpf7wirxjw
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_signal_exception
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 744
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.SignalException_SIGTERM:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmpybbsz_8t
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_stdout_callback_terminate
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 883
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.SignalException_SIGTERM:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 -u /build/tmp5axaideo
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_signal_group
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 917
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.SignalException_SIGKILL:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmp7rcy3mij
python3.8-sh>     STDOUT:
python3.8-sh>   922
python3.8-sh>   917
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_stdout_callback_kill
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 961
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.SignalException_SIGKILL:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 -u /build/tmp0ewuo3y0
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::MiscTests::test_pickling
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/mark/structures.py:603: ResourceWarning: unclosed file <_io.FileIO name=26 mode='rb+' closefd=True>
python3.8-sh>     for keyword in self.parent.keywords:
python3.8-sh>   Enable tracemalloc to get traceback where the object was allocated.
python3.8-sh>   See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.
python3.8-sh> -- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
python3.8-sh> =========================== short test summary info ============================
python3.8-sh> FAILED tests/test.py::FunctionalTests::test_general_signal - AssertionError: '0\n1\n2\n3\n43\n44\n' != '0\n1\n2\n3\n42\n43\n'
python3.8-sh> = 1 failed, 172 passed, 1 skipped, 4 deselected, 10 warnings in 62.13s (0:01:02) =
python3.8-sh> /nix/store/5wdlffjhcr4i43sfajxcvx3lvnkryh5y-stdenv-linux/setup: line 1604: pop_var_context: head of shell_variables not a function context
error: builder for '/nix/store/4gifcfg9rn7j1zygjhyzx5si3dvgffdp-python3.8-sh-2.0.2.drv' failed with exit code 1

However, if I run the same build locally with this other command, it works:

nix build nixpkgs/35130d4b4f0b8c50ed2aceb909a538c66c91d4a0#legacyPackages.x86_64-linux.python38Packages.sh -L

The build logs:

warning: error: unable to download 'https://channels.nixos.org/flake-registry.json': Problem with the SSL CA cert (path? access rights?) (77); using cached version
python3.8-sh> Sourcing python-remove-tests-dir-hook
python3.8-sh> Sourcing python-catch-conflicts-hook.sh
python3.8-sh> Sourcing python-remove-bin-bytecode-hook.sh
python3.8-sh> Sourcing pip-build-hook
python3.8-sh> Using pipBuildPhase
python3.8-sh> Using pipShellHook
python3.8-sh> Sourcing pip-install-hook
python3.8-sh> Using pipInstallPhase
python3.8-sh> Sourcing python-imports-check-hook.sh
python3.8-sh> Using pythonImportsCheckPhase
python3.8-sh> Sourcing python-namespaces-hook
python3.8-sh> Sourcing python-catch-conflicts-hook.sh
python3.8-sh> Sourcing pytest-check-hook
python3.8-sh> Using pytestCheckPhase
python3.8-sh> unpacking sources
python3.8-sh> unpacking source archive /nix/store/v6hbjcc5ay3694bg19zjbhrn00f7k2rj-source
python3.8-sh> source root is source
python3.8-sh> setting SOURCE_DATE_EPOCH to timestamp 315619200 of file source/tox.ini
python3.8-sh> patching sources
python3.8-sh> configuring
python3.8-sh> no configure script, doing nothing
python3.8-sh> building
python3.8-sh> Executing pipBuildPhase
python3.8-sh> Creating a wheel...
python3.8-sh> WARNING: The directory '/homeless-shelter/.cache/pip' or its parent directory is not owned or is not writable by the current user. The cache has been disabled. Check the permissions and owner of that directory. If executing pip with sudo, you should use sudo's -H flag.
python3.8-sh> Processing /build/source
python3.8-sh>   Running command Preparing metadata (pyproject.toml)
python3.8-sh>   Preparing metadata (pyproject.toml) ... done
python3.8-sh> Building wheels for collected packages: sh
python3.8-sh>   Running command Building wheel for sh (pyproject.toml)
python3.8-sh>   Building wheel for sh (pyproject.toml) ... done
python3.8-sh>   Created wheel for sh: filename=sh-2.0.2-py3-none-any.whl size=38306 sha256=a8999ec9f4a529fcdabf23c8f1c1c3601214e1321ea6e315e1e5de16518f3b68
python3.8-sh>   Stored in directory: /build/pip-ephem-wheel-cache-r77wa0r2/wheels/e1/fb/ff/3c7bf8327fe7b38e0848fbd084e404c8a61b776977c550714b
python3.8-sh> Successfully built sh
python3.8-sh> Finished creating a wheel...
python3.8-sh> Finished executing pipBuildPhase
python3.8-sh> installing
python3.8-sh> Executing pipInstallPhase
python3.8-sh> /build/source/dist /build/source
python3.8-sh> Processing ./sh-2.0.2-py3-none-any.whl
python3.8-sh> Installing collected packages: sh
python3.8-sh> Successfully installed sh-2.0.2
python3.8-sh> /build/source
python3.8-sh> Finished executing pipInstallPhase
python3.8-sh> pythonOutputDistPhase
python3.8-sh> Executing pythonOutputDistPhase
python3.8-sh> Finished executing pythonOutputDistPhase
python3.8-sh> post-installation fixup
python3.8-sh> shrinking RPATHs of ELF executables and libraries in /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2
python3.8-sh> checking for references to /build/ in /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2...
python3.8-sh> patching script interpreter paths in /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2
python3.8-sh> stripping (with command strip and flags -S -p) in  /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2/lib
python3.8-sh> shrinking RPATHs of ELF executables and libraries in /nix/store/w9cvl1gnyyqp18wybpajc5sz2cv85b96-python3.8-sh-2.0.2-dist
python3.8-sh> checking for references to /build/ in /nix/store/w9cvl1gnyyqp18wybpajc5sz2cv85b96-python3.8-sh-2.0.2-dist...
python3.8-sh> patching script interpreter paths in /nix/store/w9cvl1gnyyqp18wybpajc5sz2cv85b96-python3.8-sh-2.0.2-dist
python3.8-sh> Executing pythonRemoveTestsDir
python3.8-sh> Finished executing pythonRemoveTestsDir
python3.8-sh> running install tests
python3.8-sh> no Makefile or custom installCheckPhase, doing nothing
python3.8-sh> pythonCatchConflictsPhase
python3.8-sh> pythonRemoveBinBytecodePhase
python3.8-sh> pythonImportsCheckPhase
python3.8-sh> Executing pythonImportsCheckPhase
python3.8-sh> pytestCheckPhase
python3.8-sh> Executing pytestCheckPhase
python3.8-sh> ============================= test session starts ==============================
python3.8-sh> platform linux -- Python 3.8.17, pytest-7.2.1, pluggy-1.0.0
python3.8-sh> rootdir: /build/source
python3.8-sh> collected 178 items / 4 deselected / 174 selected                              
python3.8-sh> tests/test.py ......................s................................... [ 33%]
python3.8-sh> ........................................................................ [ 74%]
python3.8-sh> ............................................                             [100%]
python3.8-sh> =============================== warnings summary ===============================
python3.8-sh> tests/test.py::FunctionalTests::test_done_cb_exc
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 134
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.ErrorReturnCode_1:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmpogt55pcx
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_fg_alternative
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread STDIN thread for pid 208
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2606, in input_thread
python3.8-sh>       done = stdin.write()
python3.8-sh>     File "/build/source/sh.py", line 2919, in write
python3.8-sh>       chunk = self.get_chunk()
python3.8-sh>     File "/build/source/sh.py", line 2860, in fn
python3.8-sh>       chunk = stdin.read(bufsize)
python3.8-sh>     File "/nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/capture.py", line 192, in read
python3.8-sh>       raise OSError(
python3.8-sh>   OSError: pytest: reading from stdin while output is captured!  Consider using `-s`.
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_signal_group
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 252
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.SignalException_SIGKILL:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmpiq9b8whb
python3.8-sh>     STDOUT:
python3.8-sh>   257
python3.8-sh>   252
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_stdout_callback_terminate
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 271
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.SignalException_SIGTERM:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 -u /build/tmpv1n2zfsc
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_signal_exception
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 291
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.SignalException_SIGTERM:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmp7pq1xi13
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_exit_code_with_hasattr
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 416
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.ErrorReturnCode_3:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmp8v4zvy37
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_unchecked_pipeline_failure
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 438
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.ErrorReturnCode_2:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmp3b9q52va
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_stdout_callback_kill
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 547
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.SignalException_SIGKILL:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 -u /build/tmpvwu0_2xo
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> tests/test.py::FunctionalTests::test_unchecked_producer_failure
python3.8-sh>   /nix/store/xi3g7v0264imbbxn5pkflgvglmajr1cm-python3.8-pytest-7.2.1/lib/python3.8/site-packages/_pytest/threadexception.py:73: PytestUnhandledThreadExceptionWarning: Exception in thread background thread for pid 1002
python3.8-sh>   Traceback (most recent call last):
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 932, in _bootstrap_inner
python3.8-sh>       self.run()
python3.8-sh>     File "/nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/lib/python3.8/threading.py", line 870, in run
python3.8-sh>       self._target(*self._args, **self._kwargs)
python3.8-sh>     File "/build/source/sh.py", line 1654, in wrap
python3.8-sh>       fn(*rgs, **kwargs)
python3.8-sh>     File "/build/source/sh.py", line 2656, in background_thread
python3.8-sh>       handle_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 2347, in fn
python3.8-sh>       return self.command.handle_command_exit_code(exit_code)
python3.8-sh>     File "/build/source/sh.py", line 838, in handle_command_exit_code
python3.8-sh>       raise exc
python3.8-sh>   sh.ErrorReturnCode_2:
python3.8-sh>     RAN: /nix/store/7m6x0pssyw1x9rikljnq8wm3nww2xpir-python3-3.8.17/bin/python3.8 /build/tmpe24ll5_4
python3.8-sh>     STDOUT:
python3.8-sh>     STDERR:
python3.8-sh>     warnings.warn(pytest.PytestUnhandledThreadExceptionWarning(msg))
python3.8-sh> -- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
python3.8-sh> ========== 173 passed, 1 skipped, 4 deselected, 9 warnings in 49.37s ===========
python3.8-sh> Finished executing pytestCheckPhase
python3.8-sh> pytestCheckPhase completed in 49 seconds
python3.8-sh> pytestcachePhase
python3.8-sh> pytestRemoveBytecodePhase

Why the build only works fine in the local machine, but fails on nixbuild?

How can I fix it?

Is there a way to workaround the issue by pushing the locally-built derivation to nixbuild and to clear the cached build failure there?

@moduon MT-1075

[rickynils]

Thank you for reporting this, and for providing detailed instructions on how to reproduce the issue! We will look into why the test behaves differently in the nixbuild.net builder than in plain Nix.

You should be able to workaround this by simply copying the build results to nixbuild.net:

nix copy --to ssh://eu.nixbuild.net /nix/store/r8x0z0qqyafbn4l4n4b03wr32w5im6i7-python3.8-sh-2.0.2 /nix/store/w9cvl1gnyyqp18wybpajc5sz2cv85b96-python3.8-sh-2.0.2-dist