Parse artifacts after a custom build command

[Eljees]

Fixes #423.

--compile-custom-build runs the user's command, but nothing ever reads what that command produced: compilation_units stays empty, so Slither and the other consumers see a project with no sources.

Cause

In CryticCompile._compile, the call that parses the artifacts sits in the else branch, so it is skipped whenever a custom build is requested:

custom_build: None | str = kwargs.get("compile_custom_build", None)
if custom_build:
    self._run_custom_build(custom_build)
else:
    if not kwargs.get("skip_clean", False) and not kwargs.get("ignore_compile", False):
        self._platform.clean(**kwargs)
    self._platform.compile(self, **kwargs)   # <- only reached without a custom build

Fix

Every platform already supports ignore_compile (foundry.py, hardhat.py, buidler.py, embark.py, truffle.py): do not invoke the build tool, but still read the artifacts from disk. A custom build has just produced those artifacts, so that is exactly the mode that applies here. The patch reuses it instead of adding a new code path, and no platform is touched.

ignore_compile is passed as "true" rather than True because **kwargs is typed str here; the platforms only test it for truthiness, and crytic_defer_compilation already uses the same string convention.

Cleaning is still skipped for custom builds, which is the previous behaviour.

Tests

New tests/test_custom_build.py. It needs no compiler: it uses a stub AbstractPlatform, the same approach as tests/test_stale_cache_hint.py. The custom build command writes a marker file, so the test can distinguish "the command did not run" from "the artifacts were not parsed".

Before the fix (the marker assert passes, so the command did run):

>       assert platform.compile_calls, "platform.compile() was never called: no compilation units"
E       AssertionError: platform.compile() was never called: no compilation units
E       assert []
1 failed in 0.18s

After the fix: 1 passed.

Also run: ruff check crytic_compile/ tests/ (clean), ruff format --check (clean), ty check crytic_compile/ (no new diagnostics compared to master), and the compiler-independent part of the suite (test_stale_cache_hint.py, test_naming.py, test_locate_framework_root.py) - 25 passed.

[CLAassistant]

All committers have signed the CLA.

[Eljees]

Ping — this one and #702 have been open since 8 August with no review.

The CLA check is signed and green on both, but that is the only check that has run: the github-actions suites are at action_required, waiting on a maintainer to approve a workflow run. Neither PR has been through your test suite yet, and I cannot trigger that from my side.

The two are independent of each other and can be taken in either order.