don't try to be quite so clever with mangling

buildjob

@@ -28,8 +28,7 @@ env | egrep '^(CI_BUILD_REF|CI_RUNNER)' > build-env.txt
 
 # maybe set some coq flags
 if [[ -n "$MANGLE_NAMES" ]]; then
-    PREFIX=$(cat /dev/urandom | tr -dc 'a-z' | fold -w 12 | head -n 1)
-    export COQEXTRAFLAGS="$COQEXTRAFLAGS -mangle-names mangled_$PREFIX_"
+    export COQEXTRAFLAGS="$COQEXTRAFLAGS -mangle-names mangled_"
 fi
 
 # Build