CmdBuild.run_make(): Skip projects without buildable dir

The iteration order contains every project the dependency walk resolved,
including projects that are only installed as -devel packages below /opt.
Running the target in such a project ran make in a read-only, source-less
directory and failed the run.

Resolve each module against the workspace root only, and skip the target
with a notice when there is no buildable project directory. Factor the skip
notice into log_skip() so the platform-exclusion path shares it.

Signed-off-by: Jan Lindemann <jan@janware.com>
Assisted-by: unsloth/Qwen3.8-27B-GGUF:Q4_K_M with pi.dev v0.84.2

src/python/jw/pkg/cmds/projects/CmdBuild.py

@@ -94,6 +94,14 @@ class CmdBuild(Cmd):  # export
     @override
     async def _run(self, args: Namespace) -> None:
 
+        @lru_cache(maxsize = None)
+        def proj_dir(module: str) -> str | None:
+            return self.app.find_dir(
+                module,
+                pretty = False,
+                projs_roots = [self.app.projs_root],
+            )
+
         @lru_cache(maxsize = None)
         def read_deps(cur: str, dep_flavour: str) -> list[str]:
             # dep cache doesn't make a difference at all
@@ -172,20 +180,27 @@ class CmdBuild(Cmd):  # export
                         dep_tree[k].remove(d)
             return 1
 
+        def log_skip(module: str, msg: str) -> None:
+            title = f'---- {module}'
+            log(NOTICE, f',{title} >')
+            log(NOTICE, f'| {msg}<')
+            log(NOTICE, f'`{title} <')
+
         async def run_make(
             module: str, target: str, cur_project: int, num_projects: int
         ) -> None:
 
             patt = self.app.is_excluded_from_build(module)
             if patt is not None:
-                title = f'---- {module}'
-                log(NOTICE, f',{title} >')
-                log(NOTICE, f'| Configured to skip build on platform >{patt}<')
-                log(NOTICE, f'`{title} <')
+                log_skip(module, f'Configured to skip build on platform >{patt}<')
+                return
+
+            wd = proj_dir(module)
+            if wd is None:
+                log_skip(module, 'Skipping: No buildable project directory')
                 return
 
             make_cmd = ['make', target]
-            wd = self.app.find_dir(module, pretty = False)
             title = '---- [%d/%d]: Running "%s" in %s -' % (
                 cur_project,
                 num_projects,