18510, "BryantLam", "Doc: Exhaustive behavior tables for environment variables", "2021-10-02T00:16:07Z"
w.r.t. Documentation for CHPL_TARGET_COMPILER's default setting (and related default settings), the table for "The default for CHPL_TARGET_COMPILER is:" lists what happens when CHPL_TARGET_COMPILER is not set, but should probably just exhaustively list what happens when CC/CXX and CHPL_TARGET_COMPILER are set alongside it.
In my environment,
CHPL_TARGET_COMPILER is unset (I wanted to see what it got auto-detected as.)
CHPL_LLVM=bundled
CC/CXX are paths to GCC.
so it makes sense that CHPL_TARGET_COMPILER=gnu gets emitted from printchplenv, but it took a bit for me to figure out / remember why it wasn't llvm [^1].
[^1]: It would remove the need for sentences like "Note that setting CC and CXX will impact both the host and target compiler." if the behavior was exhaustively spelled out in the table.