The file "ShipItState.plist" couldn’t be opened because there is no such file

In an Electron-based app, I encountered an issue where one user was unable to update. The logs in ShipIt_stderr.log showed this message over and over:

Installation error: Error Domain=SQRLShipItRequestErrorDomain Code=2 "Could not read update request" UserInfo=0x7fe4cae09930 {NSLocalizedDescription=Could not read update request, NSUnderlyingError=0x7fe4cae07d50 "The file “ShipItState.plist” couldn’t be opened because there is no such file."}

However, ShipItState.plist did exist, but the two log files had different permissions than the plist file and the update directory:

drwxr-xr-x   7 foo  staff   238B Sep  9 17:16 .
drwx------+ 41 foo  staff   1.4K Sep  9 17:16 ..
-rw-r--r--@  1 foo  staff   6.0K Sep  9 17:24 .DS_Store
-rw-r--r--   1 foo  staff   262B Sep  9 17:16 ShipItState.plis
-rw-r--r--   1 root     staff   195K Sep  9 16:55 ShipIt_stderr.log
-rw-r--r--   1 root     staff     0B Sep  9 16:38 ShipIt_stdout.log
drwx------   4 foo  staff   136B Sep  9 17:24 update.c3etqCW

Doing a chown fixed the issue:

sudo chown foo:staff ShipIt_stderr.log ShipIt_stdout.log

It looks like others are hitting this same issue: https://github.com/atom/atom/issues/2860#issuecomment-121111312

It looks like SQRLUpdater.m has some logic around running as root/non-root, but if the log files are owned by root and being updated then I would assume it's running as root and should be able to read the ShipItState.plist file that's owned by a non-privileged user:

    NSError *targetWritableError = nil;
            BOOL gotWritable = [targetURL getResourceValue:&targetWritable forKey:NSURLIsWritableKey error:&targetWritableError];

            // If we can't determine whether it can be written, assume nonprivileged and
            // wait for another, more canonical error.
            return [SQRLShipItLauncher launchPrivileged:(gotWritable && !targetWritable.boolValue)];

Start in SQRLUpdater.m, then inspect the ShipIt_stderr.log and ShipItState.plist permission and ownership behavior described in the report. Trace the privileged versus nonprivileged launch decision and verify that updates can read the state file and complete without manually chowning the log files.