import error with bliss

[dcoudert]

Steps To Reproduce

Install bliss

./sage -i bliss
make build

Then in a sage shell trying to import a method from bliss fails.

See https://groups.google.com/g/sage-release/c/6hW5ZBQj_Uc/m/u0INpPITAQAJ

Expected Behavior

succeed

Actual Behavior

sage: from sage.graphs.bliss import canonical_form
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
Cell In[1], line 1
----> 1 from sage.graphs.bliss import canonical_form

ImportError: dlopen(/Users/dcoudert/sage/build/sage-distro/src/sage/graphs/bliss.cpython-312-darwin.so, 0x0002): Library not loaded: @rpath/libbliss.dylib
  Referenced from: <1B010892-EE55-39FD-A23A-2110910AE985> /Users/dcoudert/sage/build/sage-distro/src/sage/graphs/bliss.cpython-312-darwin.so
  Reason: tried: '/opt/homebrew/lib/libbliss.dylib' (no such file), '/System/Volumes/Preboot/Cryptexes/OS/opt/homebrew/lib/libbliss.dylib' (no such file), '/opt/homebrew/lib/libbliss.dylib' (no such file), '/System/Volumes/Preboot/Cryptexes/OS/opt/homebrew/lib/libbliss.dylib' (no such file)

Additional Information

No response

Environment

• OS: macOS 15.6.1
• Sage Version: 10.8.beta5

Checklist

• I have searched the existing issues for a bug report that matches the one I want to file, without success.
• I have read the documentation and troubleshoot guide

[dimpase]

@tobiasdiez - this one of these .pc-less libs. Reproducible on macOS at least

[tobiasdiez]

It works with conda: https://github.com/sagemath/sage/actions/runs/18294000941/job/52087930641#step:15:3982

There are few upstream bug reports about this:

• Relative rpaths are used for a pkgconfig dependency on Linux mesonbuild/meson#13046
• RPATHs to external libraries that aren't in the default library search path mesonbuild/meson#3882

Maybe one of the following would work:

3. Set LDFLAGS to -Wl,-rpath=/path/to/libdir
4. Set LD_LIBRARY_PATH in the shell when you try to run the built project (meh, not robust to opening a new shell)

The former can be done also in meson via:

add_project_link_arguments(
    '-Wl,-rpath=' + sage_local,
    language: 'c',
  )

[dcoudert]

It works with conda: https://github.com/sagemath/sage/actions/runs/18294000941/job/52087930641#step:15:3982

All doctests in bliss.pyx have the tag # optional - bliss.
I can successfully run ./sage -t src/sage/graphs/bliss.pyx
But if I try from sage.graphs.bliss import canonical_form in a sage session, it fails.

In which file should I try to add add_project_link_arguments(...) ?

[dimpase]

@tobiasdiez

The former can be done also in meson via:

add_project_link_arguments(...

but this looks like a project-wide (i.e. sagelib) setting, not something specific to bliss, and it should only be done conditionally, on failure to locate bliss as a "normal" dependency

Do you suggest to turn graphs/bliss into a subproject?

[dimpase]

There is a manual macOS-specific way to fix these:

% otool -L build/sage-distro/src/sage/graphs/bliss.cpython-313-darwin.so     
build/sage-distro/src/sage/graphs/bliss.cpython-313-darwin.so:
	@rpath/libbliss.dylib (compatibility version 0.0.0, current version 0.0.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 2000.63.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1356.0.0)

here @rpath/libbliss.dylib is pointing to the dylib in question, but it can't be found (here libbliss.dylib is located in SAGE_LOCAL/lib)

Now, run

% install_name_tool -change @rpath/libbliss.dylib /Users/dima/software/sage/local/lib/libbliss.dylib build/sage-distro/src/sage/graphs/bliss.cpython-313-darwin.so

and check that all is good:

% otool -L build/sage-distro/src/sage/graphs/bliss.cpython-313-darwin.so                                                                                  
build/sage-distro/src/sage/graphs/bliss.cpython-313-darwin.so:
	/Users/dima/software/sage/local/lib/libbliss.dylib (compatibility version 0.0.0, current version 0.0.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 2000.63.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1356.0.0)

Thus we replaced rpath with the explicit value
dima@OUCL13243 sage % ./sage
┌────────────────────────────────────────────────────────────────────┐
│ SageMath version 10.8.beta6, Release Date: 2025-10-06 │
│ Using Python 3.13.7. Type "help()" for help. │
└────────────────────────────────────────────────────────────────────┘
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Warning: this is a prerelease version, and it may be unstable. ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
sage: from sage.graphs.bliss import canonical_form
sage:

[tobiasdiez]

@tobiasdiez

The former can be done also in meson via:
add_project_link_arguments(...

but this looks like a project-wide (i.e. sagelib) setting, not something specific to bliss, and it should only be done conditionally, on failure to locate bliss as a "normal" dependency

Yes, it would affect all cython modules. Might be actually handy, since the same bug also might happen with other sage-build dependencies without pkgconfig files.

But perhaps the easiest fix would be to set DYLD_LIBRARY_PATH/LD_LIBRARY_PATH in sage-env.

[tobiasdiez]

It works with conda: https://github.com/sagemath/sage/actions/runs/18294000941/job/52087930641#step:15:3982

All doctests in bliss.pyx have the tag # optional - bliss. I can successfully run ./sage -t src/sage/graphs/bliss.pyx But if I try from sage.graphs.bliss import canonical_form in a sage session, it fails.

In the conda run the bliss feature is successfully detected: https://github.com/sagemath/sage/actions/runs/18294000941/job/52087930641#step:15:9210 (and also the tests take 2 sec), so I assume it is really working. (I don't have time to test it at the moment locally myself)

[dcoudert]

I confim that this fixes the issue

xxxx:sage dcoudert$ otool -L build/sage-distro/src/sage/graphs/bliss.cpython-312-darwin.so
build/sage-distro/src/sage/graphs/bliss.cpython-312-darwin.so:
	@rpath/libbliss.dylib (compatibility version 0.0.0, current version 0.0.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 2000.63.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1356.0.0)
xxxx:sage dcoudert$ install_name_tool -change @rpath/libbliss.dylib /Users/dcoudert/sage/local/lib/libbliss.dylib build/sage-distro/src/sage/graphs/bliss.cpython-312-darwin.so
xxxx:sage dcoudert$ otool -L build/sage-distro/src/sage/graphs/bliss.cpython-312-darwin.so
build/sage-distro/src/sage/graphs/bliss.cpython-312-darwin.so:
	/Users/dcoudert/sage/local/lib/libbliss.dylib (compatibility version 0.0.0, current version 0.0.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 2000.63.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1356.0.0)
xxxx:sage ./sage
┌────────────────────────────────────────────────────────────────────┐
│ SageMath version 10.8.beta6, Release Date: 2025-10-06              │
│ Using Python 3.12.11. Type "help()" for help.                      │
└────────────────────────────────────────────────────────────────────┘
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Warning: this is a prerelease version, and it may be unstable.     ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
sage: from sage.graphs.bliss import canonical_form
sage: