fix(publish): ensure that error code is a number (#656)

packages/publish/src/publish-command.ts

@@ -945,7 +945,12 @@ export class PublishCommand extends Command<PublishCommandOption> {
                 // avoid dumping logs, this isn't a lerna problem
                 err.name = 'ValidationError';
                 // ensure process exits non-zero
-                process.exitCode = 'errno' in err ? err.errno : 1;
+                if ('errno' in err && typeof err.errno === 'number' && Number.isFinite(err.errno)) {
+                  process.exitCode = err.errno;
+                } else {
+                  this.logger.error('', `errno "${err.errno}" is not a valid exit code - exiting with code 1`);
+                  process.exitCode = 1;
+                }
 
                 throw err;
               });