Add PKG_CONFIG_PATH environment variable support to all activation scripts

docs/changelog/2637.feature.rst

@@ -0,0 +1 @@
+Add ``PKG_CONFIG_PATH`` environment variable support to all activation scripts (Bash, Batch, PowerShell, Fish, C Shell, Nushell, and Python). The virtualenv's ``lib/pkgconfig`` directory is now automatically prepended to ``PKG_CONFIG_PATH`` on activation and restored on deactivation, enabling packages that use ``pkg-config`` during build/install to find their configuration files - by :user:`rahuldevikar`.

src/virtualenv/activation/bash/activate.sh

@@ -33,6 +33,11 @@ deactivate () {
         export TK_LIBRARY
         unset _OLD_VIRTUAL_TK_LIBRARY
     fi
+    if ! [ -z "${_OLD_PKG_CONFIG_PATH+_}" ]; then
+        PKG_CONFIG_PATH="$_OLD_PKG_CONFIG_PATH"
+        export PKG_CONFIG_PATH
+        unset _OLD_PKG_CONFIG_PATH
+    fi
 
     # The hash command must be called to get it to forget past
     # commands. Without forgetting past commands the $PATH changes
@@ -74,6 +79,10 @@ _OLD_VIRTUAL_PATH="$PATH"
 PATH="$VIRTUAL_ENV/"__BIN_NAME__":$PATH"
 export PATH
 
+_OLD_PKG_CONFIG_PATH="${PKG_CONFIG_PATH}"
+PKG_CONFIG_PATH="${VIRTUAL_ENV}/lib/pkgconfig:${PKG_CONFIG_PATH}"
+export PKG_CONFIG_PATH
+
 if [ "x"__VIRTUAL_PROMPT__ != x ] ; then
     VIRTUAL_ENV_PROMPT=__VIRTUAL_PROMPT__
 else

src/virtualenv/activation/batch/activate.bat

@@ -39,6 +39,9 @@
 @if defined TK_LIBRARY @set "_OLD_VIRTUAL_TK_LIBRARY=%TK_LIBRARY%"
 @if NOT "__TK_LIBRARY__"=="" @set "TK_LIBRARY=__TK_LIBRARY__"
 
+@if defined PKG_CONFIG_PATH @set "_OLD_PKG_CONFIG_PATH=%PKG_CONFIG_PATH%"
+@set "PKG_CONFIG_PATH=%VIRTUAL_ENV%\lib\pkgconfig;%PKG_CONFIG_PATH%"
+
 @REM if defined _OLD_VIRTUAL_PATH (
 @if not defined _OLD_VIRTUAL_PATH @goto ENDIFVPATH1
     @set "PATH=%_OLD_VIRTUAL_PATH%"

src/virtualenv/activation/batch/deactivate.bat

@@ -20,6 +20,10 @@
 @if not defined _OLD_VIRTUAL_TK_LIBRARY @set TK_LIBRARY=
 @set _OLD_VIRTUAL_TK_LIBRARY=
 
+@if defined _OLD_PKG_CONFIG_PATH @set "PKG_CONFIG_PATH=%_OLD_PKG_CONFIG_PATH%"
+@if not defined _OLD_PKG_CONFIG_PATH @set PKG_CONFIG_PATH=
+@set _OLD_PKG_CONFIG_PATH=
+
 @if not defined _OLD_VIRTUAL_PATH @goto ENDIFVPATH
     @set "PATH=%_OLD_VIRTUAL_PATH%"
     @set _OLD_VIRTUAL_PATH=

src/virtualenv/activation/cshell/activate.csh

@@ -5,7 +5,7 @@
 set newline='\
 '
 
-alias deactivate 'test $?_OLD_VIRTUAL_PATH != 0 && setenv PATH "$_OLD_VIRTUAL_PATH:q" && unset _OLD_VIRTUAL_PATH; rehash; test $?_OLD_VIRTUAL_TCL_LIBRARY != 0 && setenv TCL_LIBRARY "$_OLD_VIRTUAL_TCL_LIBRARY:q" && unset _OLD_VIRTUAL_TCL_LIBRARY || unsetenv TCL_LIBRARY; test $?_OLD_VIRTUAL_TK_LIBRARY != 0 && setenv TK_LIBRARY "$_OLD_VIRTUAL_TK_LIBRARY:q" && unset _OLD_VIRTUAL_TK_LIBRARY || unsetenv TK_LIBRARY; test $?_OLD_VIRTUAL_PROMPT != 0 && set prompt="$_OLD_VIRTUAL_PROMPT:q" && unset _OLD_VIRTUAL_PROMPT; unsetenv VIRTUAL_ENV; unsetenv VIRTUAL_ENV_PROMPT; test "\!:*" != "nondestructive" && unalias deactivate && unalias pydoc'
+alias deactivate 'test $?_OLD_VIRTUAL_PATH != 0 && setenv PATH "$_OLD_VIRTUAL_PATH:q" && unset _OLD_VIRTUAL_PATH; rehash; test $?_OLD_VIRTUAL_TCL_LIBRARY != 0 && setenv TCL_LIBRARY "$_OLD_VIRTUAL_TCL_LIBRARY:q" && unset _OLD_VIRTUAL_TCL_LIBRARY || unsetenv TCL_LIBRARY; test $?_OLD_VIRTUAL_TK_LIBRARY != 0 && setenv TK_LIBRARY "$_OLD_VIRTUAL_TK_LIBRARY:q" && unset _OLD_VIRTUAL_TK_LIBRARY || unsetenv TK_LIBRARY; test $?_OLD_PKG_CONFIG_PATH != 0 && setenv PKG_CONFIG_PATH "$_OLD_PKG_CONFIG_PATH:q" && unset _OLD_PKG_CONFIG_PATH || unsetenv PKG_CONFIG_PATH; test $?_OLD_VIRTUAL_PROMPT != 0 && set prompt="$_OLD_VIRTUAL_PROMPT:q" && unset _OLD_VIRTUAL_PROMPT; unsetenv VIRTUAL_ENV; unsetenv VIRTUAL_ENV_PROMPT; test "\!:*" != "nondestructive" && unalias deactivate && unalias pydoc'
 
 # Unset irrelevant variables.
 deactivate nondestructive
@@ -15,6 +15,13 @@ setenv VIRTUAL_ENV __VIRTUAL_ENV__
 set _OLD_VIRTUAL_PATH="$PATH:q"
 setenv PATH "$VIRTUAL_ENV:q/"__BIN_NAME__":$PATH:q"
 
+if ($?PKG_CONFIG_PATH) then
+    set _OLD_PKG_CONFIG_PATH="$PKG_CONFIG_PATH"
+    setenv PKG_CONFIG_PATH "${VIRTUAL_ENV}/lib/pkgconfig:${PKG_CONFIG_PATH}"
+else
+    setenv PKG_CONFIG_PATH "${VIRTUAL_ENV}/lib/pkgconfig"
+endif
+
 if (__TCL_LIBRARY__ != "") then
     if ($?TCL_LIBRARY) then
         set _OLD_VIRTUAL_TCL_LIBRARY="$TCL_LIBRARY"

src/virtualenv/activation/fish/activate.fish

@@ -43,6 +43,11 @@ function deactivate -d 'Exit virtualenv mode and return to the normal environmen
       end
     end
 
+    if test -n "$_OLD_PKG_CONFIG_PATH"
+        set -gx PKG_CONFIG_PATH "$_OLD_PKG_CONFIG_PATH"
+        set -e _OLD_PKG_CONFIG_PATH
+    end
+
     if test -n "$_OLD_VIRTUAL_PYTHONHOME"
         set -gx PYTHONHOME "$_OLD_VIRTUAL_PYTHONHOME"
         set -e _OLD_VIRTUAL_PYTHONHOME
@@ -77,6 +82,9 @@ deactivate nondestructive
 
 set -gx VIRTUAL_ENV __VIRTUAL_ENV__
 
+set -gx _OLD_PKG_CONFIG_PATH "$PKG_CONFIG_PATH"
+set -gx PKG_CONFIG_PATH "$VIRTUAL_ENV/lib/pkgconfig:$PKG_CONFIG_PATH"
+
 # https://github.com/fish-shell/fish-shell/issues/436 altered PATH handling
 if test (string sub -s 1 -l 1 $FISH_VERSION) -lt 3
     set -gx _OLD_VIRTUAL_PATH (_bashify_path $PATH)

src/virtualenv/activation/nushell/activate.nu

@@ -57,7 +57,9 @@ export-env {
     } else {
         __VIRTUAL_PROMPT__
     }
-    let new_env = { $path_name: $new_path VIRTUAL_ENV: $virtual_env VIRTUAL_ENV_PROMPT: $virtual_env_prompt }
+    let old_pkg_config_path = if (has-env 'PKG_CONFIG_PATH') { $env.PKG_CONFIG_PATH } else { '' }
+    let new_pkg_config_path = $'($virtual_env)/lib/pkgconfig:($old_pkg_config_path)'
+    let new_env = { $path_name: $new_path VIRTUAL_ENV: $virtual_env VIRTUAL_ENV_PROMPT: $virtual_env_prompt PKG_CONFIG_PATH: $new_pkg_config_path }
     if (has-env 'TCL_LIBRARY')  {
         let $new_env = $new_env | insert TCL_LIBRARY __TCL_LIBRARY__
     }

src/virtualenv/activation/powershell/activate.ps1

@@ -25,6 +25,11 @@ function global:deactivate([switch] $NonDestructive) {
         }
     }
 
+    if (Test-Path variable:_OLD_PKG_CONFIG_PATH) {
+        $env:PKG_CONFIG_PATH = $variable:_OLD_PKG_CONFIG_PATH
+        Remove-Variable "_OLD_PKG_CONFIG_PATH" -Scope global
+    }
+
     if (Test-Path function:_old_virtual_prompt) {
         $function:prompt = $function:_old_virtual_prompt
         Remove-Item function:\_old_virtual_prompt
@@ -78,6 +83,11 @@ if (__TK_LIBRARY__ -ne "") {
 
 New-Variable -Scope global -Name _OLD_VIRTUAL_PATH -Value $env:PATH
 
+if (Test-Path env:PKG_CONFIG_PATH) {
+    New-Variable -Scope global -Name _OLD_PKG_CONFIG_PATH -Value $env:PKG_CONFIG_PATH
+}
+$env:PKG_CONFIG_PATH = "$env:VIRTUAL_ENV\lib\pkgconfig;$env:PKG_CONFIG_PATH"
+
 $env:PATH = "$env:VIRTUAL_ENV/" + __BIN_NAME__ + __PATH_SEP__ + $env:PATH
 if (!$env:VIRTUAL_ENV_DISABLE_PROMPT) {
     function global:_old_virtual_prompt {

src/virtualenv/activation/python/activate_this.py

@@ -27,6 +27,14 @@
 os.environ["VIRTUAL_ENV"] = base  # virtual env is right above bin directory
 os.environ["VIRTUAL_ENV_PROMPT"] = __VIRTUAL_PROMPT__ or os.path.basename(base)
 
+# Set PKG_CONFIG_PATH to include the virtualenv's pkgconfig directory
+pkg_config_path = os.path.join(base, "lib", "pkgconfig")
+existing_pkg_config_path = os.environ.get("PKG_CONFIG_PATH", "")
+if existing_pkg_config_path:
+    os.environ["PKG_CONFIG_PATH"] = os.pathsep.join([pkg_config_path, existing_pkg_config_path])
+else:
+    os.environ["PKG_CONFIG_PATH"] = pkg_config_path
+
 # add the virtual environments libraries to the host python import mechanism
 prev_length = len(sys.path)
 for lib in __LIB_FOLDERS__.split(os.pathsep):

tests/unit/activation/test_bash.py

@@ -46,6 +46,13 @@ def __init__(self, dest):
     # The teardown logic is always present in deactivate()
     assert "unset _OLD_VIRTUAL_TCL_LIBRARY" in content
     assert "unset _OLD_VIRTUAL_TK_LIBRARY" in content
+    assert "unset _OLD_PKG_CONFIG_PATH" in content
+
+    # PKG_CONFIG_PATH is always set
+    assert '_OLD_PKG_CONFIG_PATH="${PKG_CONFIG_PATH}"' in content
+    assert 'PKG_CONFIG_PATH="${VIRTUAL_ENV}/lib/pkgconfig:${PKG_CONFIG_PATH}"' in content
+    assert "export PKG_CONFIG_PATH" in content
+    assert 'PKG_CONFIG_PATH="$_OLD_PKG_CONFIG_PATH"' in content
 
     if present:
         assert 'if [ /path/to/tcl != "" ]; then' in content

tests/unit/activation/test_batch.py

@@ -74,6 +74,13 @@ def __init__(self, dest):
     deactivate_content = (creator.bin_dir / "deactivate.bat").read_text(encoding="utf-8")
 
     # THEN
+    # PKG_CONFIG_PATH is always set
+    assert '@if defined PKG_CONFIG_PATH @set "_OLD_PKG_CONFIG_PATH=%PKG_CONFIG_PATH%"' in activate_content
+    assert '@set "PKG_CONFIG_PATH=%VIRTUAL_ENV%\\lib\\pkgconfig;%PKG_CONFIG_PATH%"' in activate_content
+    assert '@if defined _OLD_PKG_CONFIG_PATH @set "PKG_CONFIG_PATH=%_OLD_PKG_CONFIG_PATH%"' in deactivate_content
+    assert "@if not defined _OLD_PKG_CONFIG_PATH @set PKG_CONFIG_PATH=" in deactivate_content
+    assert "@set _OLD_PKG_CONFIG_PATH=" in deactivate_content
+
     if present:
         assert '@if NOT "C:\\tcl"=="" @set "TCL_LIBRARY=C:\\tcl"' in activate_content
         assert '@if NOT "C:\\tk"=="" @set "TK_LIBRARY=C:\\tk"' in activate_content

tests/unit/activation/test_csh.py

@@ -44,6 +44,14 @@ def __init__(self, dest):
     activator.generate(creator)
     content = (creator.bin_dir / "activate.csh").read_text(encoding="utf-8")
 
+    # PKG_CONFIG_PATH is always set
+    assert "test $?_OLD_PKG_CONFIG_PATH != 0" in content
+    assert 'set _OLD_PKG_CONFIG_PATH="$PKG_CONFIG_PATH"' in content
+    assert 'setenv PKG_CONFIG_PATH "${VIRTUAL_ENV}/lib/pkgconfig:${PKG_CONFIG_PATH}"' in content
+    assert 'setenv PKG_CONFIG_PATH "${VIRTUAL_ENV}/lib/pkgconfig"' in content
+    assert 'setenv PKG_CONFIG_PATH "$_OLD_PKG_CONFIG_PATH:q"' in content
+    assert "unset _OLD_PKG_CONFIG_PATH" in content
+
     if present:
         assert "test $?_OLD_VIRTUAL_TCL_LIBRARY != 0" in content
         assert "test $?_OLD_VIRTUAL_TK_LIBRARY != 0" in content

tests/unit/activation/test_fish.py

@@ -44,6 +44,11 @@ def __init__(self, dest):
     content = (creator.bin_dir / "activate.fish").read_text(encoding="utf-8")
 
     # THEN
+    # PKG_CONFIG_PATH is always set
+    assert 'set -gx _OLD_PKG_CONFIG_PATH "$PKG_CONFIG_PATH"' in content
+    assert 'set -gx PKG_CONFIG_PATH "$VIRTUAL_ENV/lib/pkgconfig:$PKG_CONFIG_PATH"' in content
+    assert "set -e _OLD_PKG_CONFIG_PATH" in content
+
     if present:
         assert "set -gx TCL_LIBRARY '/path/to/tcl'" in content
         assert "set -gx TK_LIBRARY '/path/to/tk'" in content

tests/unit/activation/test_nushell.py

@@ -36,6 +36,11 @@ def __init__(self, dest):
     content = (creator.bin_dir / "activate.nu").read_text(encoding="utf-8")
 
     # THEN
+    # PKG_CONFIG_PATH is always set
+    assert "let old_pkg_config_path = if (has-env 'PKG_CONFIG_PATH')" in content
+    assert "let new_pkg_config_path = " in content
+    assert "PKG_CONFIG_PATH: $new_pkg_config_path" in content
+
     expected_tcl = f"let $new_env = $new_env | insert TCL_LIBRARY {quoted_tcl_path}"
     expected_tk = f"let $new_env = $new_env | insert TK_LIBRARY {quoted_tk_path}"
 

tests/unit/activation/test_powershell.py

@@ -76,6 +76,13 @@ def __init__(self, dest):
     content = (creator.bin_dir / "activate.ps1").read_text(encoding="utf-8-sig")
 
     # THEN
+    # PKG_CONFIG_PATH is always set
+    assert "New-Variable -Scope global -Name _OLD_PKG_CONFIG_PATH" in content
+    assert '$env:PKG_CONFIG_PATH = "$env:VIRTUAL_ENV\\lib\\pkgconfig;$env:PKG_CONFIG_PATH"' in content
+    assert "if (Test-Path variable:_OLD_PKG_CONFIG_PATH)" in content
+    assert "$env:PKG_CONFIG_PATH = $variable:_OLD_PKG_CONFIG_PATH" in content
+    assert 'Remove-Variable "_OLD_PKG_CONFIG_PATH" -Scope global' in content
+
     if present:
         assert "if ('C:\\tcl' -ne \"\")" in content
         assert "$env:TCL_LIBRARY = 'C:\\tcl'" in content

tests/unit/activation/test_python_activator.py

@@ -2,13 +2,47 @@
 
 import os
 import sys
+from argparse import Namespace
 from ast import literal_eval
 from textwrap import dedent
 
 from virtualenv.activation import PythonActivator
 from virtualenv.info import IS_WIN
 
 
+def test_python_activator_generates_pkg_config_path(tmp_path):
+    """Test that activate_this.py sets PKG_CONFIG_PATH."""
+
+    class MockInterpreter:
+        tcl_lib = None
+        tk_lib = None
+
+    class MockCreator:
+        def __init__(self, dest):
+            self.dest = dest
+            self.bin_dir = dest / ("Scripts" if IS_WIN else "bin")
+            self.bin_dir.mkdir(parents=True)
+            self.libs = [dest / "Lib" / "site-packages"]
+            self.env_name = "test-env"
+            self.interpreter = MockInterpreter()
+            self.pyenv_cfg = {}
+
+    creator = MockCreator(tmp_path)
+    options = Namespace(prompt=None)
+    activator = PythonActivator(options)
+
+    # Generate the activation script
+    activator.generate(creator)
+
+    # Read the generated script
+    content = (creator.bin_dir / "activate_this.py").read_text(encoding="utf-8")
+
+    # Verify PKG_CONFIG_PATH is set
+    assert "PKG_CONFIG_PATH" in content
+    assert "pkg_config_path" in content
+    assert 'os.path.join(base, "lib", "pkgconfig")' in content
+
+
 def test_python(raise_on_non_source_class, activation_tester):
     class Python(raise_on_non_source_class):
         def __init__(self, session) -> None: