Improve error message if pkg.m4 couldn't be found

Check whether aclocal.m4 contains the pkg.m4 macro package after running
autoreconf and print a more helpful error message.

Thanks to 林博仁 (Buo-ren Lin) for the initial patch.

Closes: #21

1 files changed, 9 insertions, 0 deletions

diff --git a/autogen.sh b/autogen.sh
index 4e7858a5..d9c49f4c 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -69,6 +69,15 @@ autoreconf -if -Wall
 
 cd $THEDIR
 
+if ! grep -q pkg.m4 aclocal.m4; then
+    cat <<EOF
+
+Couldn't find pkg.m4 from pkg-config. Install the appropriate package for
+your distribution or set ACLOCAL_PATH to the directory containing pkg.m4.
+EOF
+    exit 1
+fi
+
 if test x$OBJ_DIR != x; then
     mkdir -p "$OBJ_DIR"
     cd "$OBJ_DIR"