build-sys: Link with gpg-error directly

We use the API, and not linking breaks the build with e.g.
`-fuse-ld=gold` in a Fedora 28 buildroot as gold doesn't do the
"search indirect dependencies" thing.

Closes: #1679
Approved by: jlebon

diff --git a/configure.ac b/configure.ac
index 896e78064cab993380b1339c937c8262091cff6e..f0907a15a1d95c5fc807c389fec52461a96051c1 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -220,6 +220,10 @@ AS_IF([ test x$have_gpgme = xno ], [
    AC_MSG_ERROR([Need GPGME_PTHREAD version $LIBGPGME_DEPENDENCY or later])
 ])
 OSTREE_FEATURES="$OSTREE_FEATURES gpgme"
+dnl This apparently doesn't ship a pkg-config file either, and we need
+dnl to link to it directly.
+OT_DEP_GPGME_CFLAGS="${OT_DEP_GPGME_CFLAGS} $(gpg-error-config --cflags)"
+OT_DEP_GPGME_LIBS="${OT_DEP_GPGME_LIBS} $(gpg-error-config --libs)"
 
 LIBARCHIVE_DEPENDENCY="libarchive >= 2.8.0"
 # What's in RHEL7.2.