…ction.

Extra diagnostics are enabled if PYMUPDF_EXCEPTIONS_VERBOSE is 2.

mupdf-1.23.7 seems ok, mupdf master causes us problems.

This is for pymupdf#2907, 'segfault trying to call clean_contents on certain pdfs with
python 3.12'.

We are not intending to fix this bug, so actually this test only runs on
rebased.

Was previously set to mupdf version.

…v().

venv():
    added `venv_quick` option, small speed up if venv directory already exists.

log():
    show caller path and fn name.

…o run.

Also don't print python backtrace after subprocess errors, as not usually
useful.

Simplified command line to be <options> followed by <commands>.

New options:
    -b: set build type (e.g. debug).
    -d: set debug build.
    -i: set pymupdf implementations to test.
    -m: same as --mupdf, sets location of mupdf.
    -p: set pytest options.
    -t: set pytest test file/function.
    -v: save time if venv directory already exists.

If tests fail, show information about re-running tests manually in venv.

Don't show python backtrace of subprocess errors, as not useful.

Avoid problems on github with valgrind tests, where classic cannot find
libmupdf.so if PyMuPDF checkout is the current directory.