1 files changed, 4 insertions, 1 deletions
diff --git a/lib/System/Unix/Unix.h b/lib/System/Unix/Unix.h
index b2c3160a41..452226f4f7 100644
--- a/lib/System/Unix/Unix.h
+++ b/lib/System/Unix/Unix.h
@@ -70,6 +70,9 @@
 /// string and the Unix error number given by \p errnum. If errnum is -1, the
 /// default then the value of errno is used.
 /// @brief Make an error message
+///
+/// If the error number can be converted to a string, it will be
+/// separated from prefix by ": ".
 static inline bool MakeErrMsg(
   std::string* ErrMsg, const std::string& prefix, int errnum = -1) {
   if (!ErrMsg)
@@ -94,7 +97,7 @@ static inline bool MakeErrMsg(
   // but, oh well, just use a generic message
   sprintf(buffer, "Error #%d", errnum);
 #endif
-  *ErrMsg = prefix + buffer;
+  *ErrMsg = prefix + ": " + buffer;
   return true;
 }