From jhbuild/modulesets/gnome-suites-core-deps-latest.modules:
<autotools id="glibmm-2.4" supports-non-srcdir-builds="no">
<autotools id="glibmm" supports-non-srcdir-builds="no">
I've used jhbuild to build glibmm without the
supports-non-srcdir-builds="no" parameter. I can't see nay problem.
Everything seems to work normally in a builddir != sourcedir build:
make, make install, make check, make distcheck.
Emmanuele, you added supports-non-srcdir-builds="no" to
gnome-suites-core-deps-3.22.modules with commit
https://gitlab.gnome.org/GNOME/jhbuild/commit/c283a4b6af5d94cea7c90e5587fffad8e7ef0413
Do you remember why you did that?
I added it while I was going through the whole modulesets in GNOME with jhbuild using a different build directory by default, and disabling non-sourcedir builds for modules that failed to build.
I apologise for the lack of a decent commit message: I was likely trying to keep the build going and pushed too quickly.
If glibmm can now use non-sourcedir builds without failing, feel absolutely free to change the moduleset.
Ciao,
Emmanuele.