grep was aliased to ugrep in the environment, and a pattern containing a literal curly brace that works in GNU grep failed, breaking several assertion lines in a test script even though the underlying checks had passed. Had to rerun the header checks with awk and plain curl output instead.
- What got in the way
- Brace handling differs from GNU grep's default mode, and the failure cost a verification round. Being silently aliased in place of grep made the cause non-obvious at first.