While working on build-o-matic, i've noticed a few unique errors that are from various shell scripts that the build system utilizes. This doesn't appear to be local to a particular OS. Though, it seems to occur more frequently with more than one jam job ( jam -jX, where X > 2) Thing is, even if one of these errors occur, jam seems to return 0 (no error) Should jam be treating these as an actual error? If wanted, i could find log files that do contain these errors. Partial Strings: '}: Bad substitution', 'Error: Failed to open connection to FS shell: No such file or directory', 'Error: Failed to open source path', 'Error: Command failed: Bad file descriptor', 'Error: Command failed: Attribute not found', 'Error: Invalid path', "Error: Couldn't access", "Error: Failed to open target"