`make gen` could not run with `-j` because inter-target dependency edges
were missing. Multiple recipes compile `coderd/rbac` (which includes
generated files like `object_gen.go`), and without explicit ordering,
parallel runs produced syntax errors from mid-write reads.
Three main changes:
**Dependency graph fixes** declare the compile-time chain through
`coderd/rbac` so that `object_gen.go` is written before anything that
imports it is compiled. The DB generation targets use a GNU Make 4.3+
grouped target (`&:`) so Make knows `generate.sh` co-produces
`querier.go`, `unique_constraint.go`, `dbmetrics`, and `dbauthz` in a
single invocation. `SKIP_DUMP_SQL=1` avoids re-entrant `make` inside
`generate.sh` when the Makefile already guarantees `dump.sql` is fresh.
**`scripts/atomicwrite` package** replaces `os.WriteFile` in all gen
scripts with a temp-file-in-same-dir + rename pattern, preventing
interrupted runs from leaving partial files.
**`.PRECIOUS` and shell atomic writes** protect git-tracked generated
files from Make's default delete-on-error behavior. Since these files
are committed, deletion is worse than staleness -- `git restore` is the
recovery path.
CI now runs `make -j --output-sync -B gen` (~32s, down from ~85s
serial).
| Scenario | Before | After |
|-----------------------------------|--------------------|----------|
| `make gen` (serial) | 95s | 95s |
| `make -j gen` (parallel) | race error | **22s** |
| CI `make -j --output-sync -B gen` | forced serial ~85s | **~32s** |