Fix: Honor linter rules in CI and locally (#15492)

RUSTFLAGS take precedence over `target.<triple>.rustflags`. Therefore,
setting the env var globally in CI would always override whatever linter
rules are allowed or denied in .cargo/config.toml.

With this change, we ensure that problems are detected both in CI and
locally, using either cargo clippy or lint.js.

.github/workflows/ci.yml

@@ -140,9 +140,6 @@ jobs:
           service_account_key: ${{ secrets.GCP_SA_KEY }}
           export_default_credentials: true
 
-      - name: Error on warning
-        run: echo "RUSTFLAGS=-D warnings" >> $GITHUB_ENV
-
       - name: Configure canary build
         if: |
           matrix.job == 'test' &&

ext/flash/sendfile.rs

@@ -21,8 +21,8 @@ impl SendFile {
       let count = 0x7ffff000;
       let mut offset = self.written as libc::off_t;
 
-      // SAFETY: call to libc::sendfile()
       let res =
+        // SAFETY: call to libc::sendfile()
         unsafe { libc::sendfile(self.io.1, self.io.0, &mut offset, count) };
       if res == -1 {
         Err(io::Error::last_os_error())

tools/lint.js

@@ -111,7 +111,7 @@ async function clippy() {
   }
 
   const { success } = await Deno.spawn("cargo", {
-    args: cmd,
+    args: [...cmd, "--", "-D", "warnings"],
     stdout: "inherit",
     stderr: "inherit",
   });