FIX Inkscape version detection when diagnostic messages precede version output

[Copilot]

On some Linux systems (e.g. CentOS/RHEL), Inkscape prints a libgc workaround message before the version line, causing INKSCAPE_VERSION to be set to _INKSCAPE_GC=disable instead of the actual version string. This breaks any LooseVersion comparison (e.g. in svgoverlay.get_texture and utils.add_roi), raising a TypeError.

Changes

• cortex/testing_utils.py — inkscape_version()

  • Replace blind output.split()[1] with line-by-line parsing of combined stdout+stderr
  • Return the version token only from the line starting with Inkscape
  • Switch from check_output to sp.run(..., check=True) to capture both streams

• cortex/tests/test_testing_utils.py — new unit tests for inkscape_version() covering:

  • Inkscape not installed → None
  • Clean stdout → version parsed correctly
  • Newer version string format (e.g. 1.2.2)
  • Diagnostic noise before version line on stdout (regression test for the bug)
  • Diagnostic noise on stderr, version on stdout
  • No Inkscape line in output → None
  • Non-zero exit code → CalledProcessError propagated

Before — breaks when Inkscape emits extra output:

output = sp.check_output(cmd.split(), stderr=sp.PIPE)
version = output.split()[1]  # grabs '_INKSCAPE_GC=disable' instead of '1.2.2'

After — robust to diagnostic noise on stdout or stderr:

result = sp.run(cmd.split(), stdout=sp.PIPE, stderr=sp.PIPE, check=True)
combined = result.stdout + result.stderr
for line in combined.decode('utf-8').splitlines():
    if line.strip().startswith('Inkscape'):
        return line.split()[1]  # always '1.2.2'

[mvdoc]

@copilot add tests

[Copilot]

@copilot add tests

Added 7 unit tests in cortex/tests/test_testing_utils.py (commit 96c354d), covering:

• Inkscape not installed → None
• Clean stdout → version parsed correctly
• Newer version string (e.g. 1.2.2)
• Diagnostic noise before version line on stdout — regression test for the bug
• Diagnostic noise on stderr, version on stdout
• No Inkscape line in output → None
• Non-zero exit code → CalledProcessError propagated