autoconf: More informative errors when pkg-config macros undefined
Added a check that PKG_PROG_PKG_CONFIG is defined before calling it so
the user can see a proper error. Without it, the generated configure
script will just pass on to the next statement and bomb with a strange
shell syntax error.
diff --git a/configure.ac b/configure.ac
index 4cd641b..40c39b9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -28,6 +28,12 @@
AC_PATH_PROG(MAKE, make)
AC_PATH_PROG(MKDEP, makedepend)
AC_PATH_PROG(SED, sed)
+
+dnl Make sure the pkg-config macros are defined
+m4_ifdef([PKG_PROG_PKG_CONFIG],,[
+ AC_MSG_ERROR([The pkg-config autoconf macros are not defined.
+ Did you run 'make configure'?])]
+)
PKG_PROG_PKG_CONFIG()
dnl LIB_DIR - library basename