Hint about not running autogen.sh when building from release archive

Related to #418.

diff --git a/autogen.sh b/autogen.sh
index eb3d9ba12d50fd764e50a61c1d90fa5cb87adc17..00c9f52c85e44d129fc01eb336b6ccb6f321bde8 100755 (executable)
--- a/autogen.sh
+++ b/autogen.sh
@@ -2,7 +2,19 @@
 
 set -e
 
-rm -f dev_mode_disabled
+if [ -f dev_mode_disabled ]; then
+    cat <<EOF >&2
+Error: It looks like you are building ccache from a release archive. If so,
+there is no need to run autoconf.sh. See INSTALL.md for further instructions.
+
+If you do want to the enable the development mode, delete the file
+dev_mode_disabled first, but it's probably a better idea to work with the
+proper ccache Git repository directly as described on
+<https://ccache.dev/repo.html>.
+EOF
+    exit 1
+fi
+
 autoheader
 autoconf
 echo "Now run ./configure and make"