Add a more robust check for 'guild'.

* configure.ac: Add a more robust check for 'guild'.
* build-aux/gitlab-ci.yml: Do not make a 'guild' symlink.

build-aux/gitlab-ci.yml

@@ -9,10 +9,6 @@ before_script:
       pkg-config
   - which guile
   - guile --version
-  # Guile's M4 macros are pretty sure that the `guild' binary has to
-  # have the exact same suffix as the `guile' binary.  In practice,
-  # this means we need a `guild-2.2' binary.
-  - ln -s /usr/bin/guild /usr/bin/guild-2.2
 
 test:
   script:

configure.ac

@@ -10,6 +10,12 @@ AM_SILENT_RULES([yes])
 GUILE_PKG([2.2 2.0])
 GUILE_PROGS
 
+AC_ARG_VAR([GUILD], [guild (Guile compiler) command])
+AS_IF([test "x$GUILD" = "x"],
+  [PKG_CHECK_VAR([GUILD], [guile-$GUILE_EFFECTIVE_VERSION], [guild], [],
+    [AC_MSG_ERROR(m4_normalize([
+      'guild' binary not found; please check your Guile installation.]))])])
+
 AC_PATH_PROG([GENHTML], [genhtml])
 AM_CONDITIONAL([HAVE_GENHTML], [test -n $GENHTML])