HostCacheSourceStamp already edits a module source with a backdated
mtime and expects the PCM cache to be rebuilt. Its own header names the
real danger, a project.so compiled against declarations that no longer
match the process it is loaded into, but it never looked at the
project.so. It now records the file's mtime before the edit and expects
a newer one after it, with project.cpp untouched, so only the stamp can
force the rebuild.
Fails without the previous commit: the stamp was the version string
alone and the project.so was reused.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Three follow-ons to the stale-build report, all cases of an identity not
capturing something that changes the output.
The host PCM cache under <cache>/crafter.build/<target>-<march>/ is shared by
every crafter-build on the machine, and freshness was a per-file mtime
comparison. That cannot tell "this PCM is newer than my source" from "this PCM
was built from different sources that happen to be newer", so a package install
and a working checkout — or two checkouts of different versions — silently
compiled their project.cpp against each other's declarations. Invalidation now
keys on a stamp over the bytes of every module source, which also covers the
case one file's mtime never could: the cached PCMs import each other, so a
change to :Interface invalidates :Clang's PCM with Crafter.Build-Clang.cppm
untouched.
Project args ApplyStandardArgs does not itself interpret are now folded into
VariantId. Such a flag typically decides what gets compiled or bundled — the
report's example is --no-webgpu dropping entries from cfg.files — and without it
both settings shared one bin dir and interleaved their outputs there, leaving a
bundle matching neither. Sorted and deduplicated so flag order doesn't split the
cache, and inherited by test Configurations.
`crafter-build clean` removes the project's bin/ and build/ trees. It
deliberately does not load project.cpp: cleaning is most often reached when
something is already wrong, and a clean that first needs the project to compile
is useless exactly then.
