pip fails to install PyGObject

[voidtrance]

I am trying to install PyGObject into my virtual environment on a Fedora 42 system but it is failing during a missing dependency:

Output:
Collecting PyGObject (from -r ./virtualenv.txt (line 9))
  Using cached pygobject-3.52.3.tar.gz (1.2 MB)
  Installing build dependencies ... error
  error: subprocess-exited-with-error
  
  × pip subprocess to install build dependencies did not run successfully.
  │ exit code: 1
  ╰─> [75 lines of output]
      Collecting meson-python>=0.12.1
        Using cached meson_python-0.18.0-py3-none-any.whl.metadata (2.8 kB)
      Collecting pycairo>=1.16
        Using cached pycairo-1.28.0.tar.gz (662 kB)
        Installing build dependencies: started
        Installing build dependencies: finished with status 'done'
        Getting requirements to build wheel: started
        Getting requirements to build wheel: finished with status 'done'
        Installing backend dependencies: started
        Installing backend dependencies: finished with status 'done'
        Preparing metadata (pyproject.toml): started
        Preparing metadata (pyproject.toml): finished with status 'error'
        error: subprocess-exited-with-error
      
        × Preparing metadata (pyproject.toml) did not run successfully.
        │ exit code: 1
        ╰─> [48 lines of output]
            + meson setup /tmp/pip-install-tgctgvfn/pycairo_cb9c1f8bdd81416f8c68e9a26475394d /tmp/pip-install-tgctgvfn/pycairo_cb9c1f8bdd81416f8c68e9a26475394d/.mesonpy-xm0mp6_0 -Dbuildtype=release -Db_ndebug=if-release -Db_vscrt=md -Dwheel=true -Dtests=false --native-file=/tmp/pip-install-tgctgvfn/pycairo_cb9c1f8bdd81416f8c68e9a26475394d/.mesonpy-xm0mp6_0/meson-python-native-file.ini
            The Meson build system
            Version: 1.8.2
            Source dir: /tmp/pip-install-tgctgvfn/pycairo_cb9c1f8bdd81416f8c68e9a26475394d
            Build dir: /tmp/pip-install-tgctgvfn/pycairo_cb9c1f8bdd81416f8c68e9a26475394d/.mesonpy-xm0mp6_0
            Build type: native build
            Project name: pycairo
            Project version: 1.28.0
            C compiler for the host machine: cc (gcc 15.1.1 "cc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2)")
            C linker for the host machine: cc ld.bfd 2.44-3
            Host machine cpu family: x86_64
            Host machine cpu: x86_64
            Program python3 found: YES (/home/mitko/vortex/env/bin/python3)
            Compiler for C supports arguments -Wall: YES
            Compiler for C supports arguments -Warray-bounds: YES
            Compiler for C supports arguments -Wcast-align: YES
            Compiler for C supports arguments -Wconversion: YES
            Compiler for C supports arguments -Wextra: YES
            Compiler for C supports arguments -Wformat=2: YES
            Compiler for C supports arguments -Wformat-nonliteral: YES
            Compiler for C supports arguments -Wformat-security: YES
            Compiler for C supports arguments -Wimplicit-function-declaration: YES
            Compiler for C supports arguments -Winit-self: YES
            Compiler for C supports arguments -Winline: YES
            Compiler for C supports arguments -Wmissing-format-attribute: YES
            Compiler for C supports arguments -Wmissing-noreturn: YES
            Compiler for C supports arguments -Wnested-externs: YES
            Compiler for C supports arguments -Wold-style-definition: YES
            Compiler for C supports arguments -Wpacked: YES
            Compiler for C supports arguments -Wpointer-arith: YES
            Compiler for C supports arguments -Wreturn-type: YES
            Compiler for C supports arguments -Wshadow: YES
            Compiler for C supports arguments -Wsign-compare: YES
            Compiler for C supports arguments -Wstrict-aliasing: YES
            Compiler for C supports arguments -Wundef: YES
            Compiler for C supports arguments -Wunused-but-set-variable: YES
            Compiler for C supports arguments -Wswitch-default: YES
            Compiler for C supports arguments -Wno-missing-field-initializers: YES
            Compiler for C supports arguments -Wno-unused-parameter: YES
            Compiler for C supports arguments -fno-strict-aliasing: YES
            Compiler for C supports arguments -fvisibility=hidden: YES
            Found pkg-config: YES (/usr/bin/pkg-config) 2.3.0
            Found CMake: /usr/bin/cmake (3.31.6)
            Run-time dependency cairo found: NO (tried pkgconfig and cmake)
      
            ../cairo/meson.build:31:12: ERROR: Dependency "cairo" not found, tried pkgconfig and cmake
      
            A full log can be found at /tmp/pip-install-tgctgvfn/pycairo_cb9c1f8bdd81416f8c68e9a26475394d/.mesonpy-xm0mp6_0/meson-logs/meson-log.txt
            [end of output]
      
        note: This error originates from a subprocess, and is likely not a problem with pip.
      error: metadata-generation-failed
      
      × Encountered error while generating package metadata.
      ╰─> See above for output.
      
      note: This is an issue with the package mentioned above, not pip.
      hint: See above for details.
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.

[notice] A new release of pip is available: 24.3.1 -> 25.1.1
[notice] To update, run: python3 -m pip install --upgrade pip
error: subprocess-exited-with-error

× pip subprocess to install build dependencies did not run successfully.
│ exit code: 1
╰─> See above for output.

note: This error originates from a subprocess, and is likely not a problem with pip.
make: *** [Makefile:62: venv] Error 1

I have two questions:
1. How can I get PyGObject installed?
2. Why is PIP trying to build Cairo? I have everything that is need to use PyGObject on the base system. Running this small code in the interpreter directly does work. Shouldn't it just pull a pre-built package? By having to build all of the dependencies for PyGObject, the system would have to have the full Gtk development environment, which just doesn't seem right.

>>> import gi
>>> gi.require_version("Gtk", "3.0")
... gi.require_version('GLib', '2.0')
... from gi.repository import Gtk, GLib, GObject, GdkPixbuf, Gdk
... 
>>> w = Gtk.Window()
>>> w.show_all()
>>> Gtk.main()

[wabbity]

By having to build all of the dependencies for PyGObject, the system would have to have the full Gtk development environment, which just doesn't seem right.

It is, because you have created an isolated environment, it is totally separate to the main system!

Actually, main packages I dunno, but try: pip install pycairo

[Larz60+]

pip is not native to fedora, so may (or may not) run into problems.
Have you tried: https://developer.fedoraproject.org/tech...bject.html ?