[gentoo-dev] [PATCH 2/2] distutils-r1.eclass: Skip build_ext when there no .c/.pyx files

[Michał Górny]

Skip issuing build_ext when there appears to be no .c/.pyx files.
Since starting setuptools is expensive, this gives a major speedup
to building pure Python packages.  If the check misfires, the worst
that can happen is that C extensions will be built serialized.

Signed-off-by: Michał Górny <mgorny@g.o>
---
 eclass/distutils-r1.eclass | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/eclass/distutils-r1.eclass b/eclass/distutils-r1.eclass
index 1a0097647c41..4d9db7586371 100644
--- a/eclass/distutils-r1.eclass
+++ b/eclass/distutils-r1.eclass
@@ -1133,7 +1133,12 @@ distutils-r1_python_compile() {
 		fi
 
 		if [[ ${DISTUTILS_USE_PEP517} && ${GPEP517_TESTING} ]]; then
-			esetup.py build_ext -j "${jobs}" "${@}"
+			# issue build_ext only if it looks like we have something
+			# to build; setuptools is expensive to start
+			if [[ -n $(find '(' -name '*.c' -o -name '*.pyx' ')' -print -quit) ]]
+			then
+				esetup.py build_ext -j "${jobs}" "${@}"
+			fi
 		else
 			esetup.py build -j "${jobs}" "${@}"
 		fi
-- 
2.35.1