We used to have the glib-genmarshal and glib-mkenums build utilities shipped as part of dev-libs/glib itself. They got ported upstream to python and now we've split them out into a separate python-single-r1 package, which keeps runtime glib consumers free of python runtime dependencies, which has its use cases.
At this point, dev-libs/glib pulls in dev-util/glib-utils itself for migration purposes, but we want to get rid of that, as it defeats the purpose.
So if your packages build uses glib-mkenums or glib-genmarshal at build time, please add a build depend on glib-utils. With EAPI-7 I believe it'd be a BDEPEND, as it's about generating C sources and headers.
Note that sometimes the build system does use the utility, but also ships pregenerated enum or marshaller sources/headers in a release tarball (and has rules to not call the utility if mtime of generated stuff is newer than the source metadata fed to the utilities). In such a case, the build depend might not be necessary after all, but it's a build only dep that most people have anyways, so it probably doesn't hurt to safeguard for future tarballs or timestamp issues.
In meson, this build depend is implicit if any meson.build file calls genmarshal, mkenums or mkenums_simple from the gnome module. This can be typically found with a simple grep -r -e 'mkenums' -e 'genmarshal' --include='meson.build' or similar.
With autotools, it isn't uncommon to have a check for the utility, but if not found the m4 variable is left empty, and then it still gets executed. This often results in the build system trying to execute something that was actually meant to be passed as first argument to the utility. Often this is e.g. "--fhead".
tl;dr, if build fails without glib-utils present (Toralf is running some tinderbox instances where it's force unmerged) about a missing glib-genmarshal, glib-mkenums or weird calls to --fhead, add a glib-utils build depend (BDEPEND with EAPI-7, DEPEND with older).
The bug has been closed via the following commit(s):
Author: Göktürk Yüksek <firstname.lastname@example.org>
AuthorDate: 2018-11-08 21:34:23 +0000
Commit: Göktürk Yüksek <email@example.com>
CommitDate: 2018-11-08 21:38:34 +0000
media-sound/playerctl: add missing dep on dev-util/glib-utils #667324
Package-Manager: Portage-2.3.51, Repoman-2.3.11
Signed-off-by: Göktürk Yüksek <firstname.lastname@example.org>
media-sound/playerctl/playerctl-2.0.0_rc1.ebuild | 1 +
1 file changed, 1 insertion(+)
Sorry, meant to close #670676
*** Bug 682518 has been marked as a duplicate of this bug. ***