Limit ephemeral filename length

diff --git a/mkosi/qemu.py b/mkosi/qemu.py
index c0350032201e7dd3bfde76a8a6d2224d5d714f83..6efcdff9da83956157175b3921f2a233e192b912 100644 (file)
--- a/mkosi/qemu.py
+++ b/mkosi/qemu.py
@@ -438,8 +438,9 @@ def vsock_notify_handler() -> Iterator[tuple[str, dict[str, str]]]:
 def copy_ephemeral(config: Config, src: Path) -> Iterator[Path]:
     src = src.resolve()
     # tempfile doesn't provide an API to get a random filename in an arbitrary directory so we do this
-    # instead.
-    tmp = src.parent / f"{src.name}-{uuid.uuid4().hex}"
+    # instead. Limit the size to 16 characters as the output name might be used in a unix socket path by vmspawn and
+    # needs to fit in 108 characters.
+    tmp = src.parent / f"{src.name}-{uuid.uuid4().hex[:16]}"
 
     try:
         def copy() -> None: