lfs: improve the error message for a missing remote blob It seems better to print the name known to the user, not the internal file. The previous code unconditionally set 'p.filename'. That potentially made the attribute None, and would be printed as such in _gitlfsremote._checkforservererror() instead of "unknown". Normally, files are printed relative to CWD, but I don't see a way to get the repo path to make that adjustment. The test modified here apparently only runs within Facebook, but a print statement confirmed the name change. I tried uploading the blob to a different remote store (so the git server never saw it), and also killing the git server and removing the blob directory, and removing the 'lfs.db' file. All resulted in a message: abort: LFS server claims required objects do not exist: bdc26931acfb734b142a8d675f205becf27560dc461f501822de13274fe6fc8a! So I have no idea how to make this test generally runnable.