pio: specify revision as prerelease

code/scripts/espurna_utils/git.py

@@ -13,7 +13,7 @@ def app_inject_revision(env):
     revision = env.get("ESPURNA_RELEASE_REVISION", "")
     if not revision:
         try:
-            revision = git("rev-parse", "--short=8", "HEAD")
+            revision = ".git" + git("rev-parse", "--short=8", "HEAD")
         except: # pylint: disable=broad-except
             pass