CI: test for cross-compilers in makedepends (MR 2272)

Related: #1128

[ci:skip-build] Will not finish in 3h on CI. Builds locally.

.gitlab-ci/testcases/test_kernel.py

@@ -18,7 +18,18 @@ def test_aports_kernel(args):
 
     for path in glob.iglob(f"{args.aports}/**/linux-*/APKBUILD", recursive=True):
         apkbuild = pmb.parse.apkbuild(args, path)
+        aport_name = os.path.basename(os.path.dirname(path))
 
         if "pmb:cross-native" not in apkbuild["options"]:
-            raise RuntimeError("\"pmb:cross-native\" missing in"
-                               f" options= line: {path}")
+            raise RuntimeError(f"{aport_name}: \"pmb:cross-native\" missing in"
+                               " options= line")
+
+        # cross-compilers should not be in makedepends
+        for ccc in ["gcc-armv7", "gcc-armhf", "gcc-aarch64",
+                    "gcc4-armv7", "gcc4-armhf", "gcc4-aarch64",
+                    "gcc6-armv7", "gcc6-armhf", "gcc6-aarch64"]:
+            if ccc in apkbuild["makedepends"]:
+                raise RuntimeError(f"{aport_name}: Cross-compiler ({ccc}) should"
+                                   " not be explicitly specified in makedepends!"
+                                   " pmbootstrap installs cross-compiler"
+                                   " automatically.")