@section Hashing and stamping
All targets are checksummed if target's @file{ctime} differs from the
-previous one, or @env{REDO_INODE_NO_TRUST} environment variable is set.
+previous one, or @env{$REDO_INODE_NO_TRUST} environment variable is set.
@command{apenwarr/redo} gives
@url{https://redo.readthedocs.io/en/latest/FAQImpl/#why-not-always-use-checksum-based-dependencies-instead-of-timestamps, many reasons}
why every time checksumming is bad, but in my opinion in practice all of