historical: use tmp logfile to avoid NFS

experiments/historical_build.py

@@ -90,8 +90,9 @@ class HistoricalCompilation(Experiment, ClangHashHelper):
                            "commit-hash": self.metadata["project-hash"],
                            'builds': []}
 
-        if self.mode.value == "ccache-clang-hash":
-            os.environ["CLANG_HASH_LOGFILE"] = self.clang_hash_stats.path
+        hash_log = self.tmp_directory.new_file("clang-hash.log")
+        if "clang-hash" in self.mode.value:
+            os.environ["CLANG_HASH_LOGFILE"] = hash_log.path
 
         with self.project as src_path:
             (commits, _) = shell("cd %s; git log --no-merges --oneline --topo-order --format='%%H %%P %%s'", src_path)
@@ -153,6 +154,10 @@ class HistoricalCompilation(Experiment, ClangHashHelper):
         if "ccache" in self.mode.value:
             shell("ccache -s > %s", self.ccache_stats.path)
 
+        # Copy Log to the result directory
+        with open(self.hash_log.path) as fd:
+            self.clang_hash_stats.value = fd.read()
+
     def variant_name(self):
         return "%s-%s"%(self.project_name(), self.metadata['mode'])