27975, "jabraham17", "[Bug]: '--fast-followers' can leave behind unresolved code", "2025-10-28T22:29:29Z"
The following program fails during codegen with error: could not find C type for _unknown_chpl. This is indicative of a variable not being resolved and being left with type unknown
use BlockCycDist;
var myBlockCyclicDist = {1..100} dmapped new blockCycDist(1, 4);
writeln(myBlockCyclicDist);
$ chpl bug.chpl --baseline --fast-followers
error: could not find C type for _unknown_chpl
$ chpl bug.chpl --baseline
# ok
$ chpl bug.chpl --no-dead-code-elimination --fast-followers
error: could not find C type for _unknown_chpl
The error occurs when --no-dead-code-elimination is thrown, because that pass is covering up the unresolved variable by removing it. Which is to say, for normal compilation this really isn't an issue (especially since this is dead code and the branch would never execute anyway). But if a user is turning off optimization passes to debug code, they will may hit this