Apparently, one cannot, should not, and is morally reprehensible should one attempt to modify .chpl source files between python runs.
Lydia phrased it thusly:
you need to reinstall the pyChapel module, because it copied them to a location where it would expect to look for them and uses the cached copy when it re-compiles
cached versions of compiled .chpl source files should get replaced when the source file is more recent than the compiled version
Apparently, one cannot, should not, and is morally reprehensible should one attempt to modify
.chpl
source files between python runs.Lydia phrased it thusly: