Meteor crashes on server start with promise_server.js error - meteor

Question

I am seeing this in Meteor 1.8.0, don't know if it's in earlier versions or not. I just made some code changes, and when I meteor run, the server immediately crashes with this head-scratcher:
C:\Users\holmesa\AppData\Local\.meteor\packages\meteor-tool\1.8.0\mt-os.windows.x86_64\dev_bundle\lib\node_modules\meteor-promise\promise_server.js:218
throw error;
^
undefined
=> awaited here:
at Promise.await (C:\Users\holmesa\AppData\Local\.meteor\packages\meteor-tool\1.8.0\mt-os.windows.x86_64\dev_bundle\lib\node_modules\meteor-promise\promise_server.js:60:12)
at JsOutputResource.finalize (C:\tools\isobuild\compiler-plugin.js:891:7)
at JsOutputResource.hasPendingErrors (C:\tools\isobuild\compiler-plugin.js:918:10)
at JsOutputResource.reportPendingErrors (C:\tools\isobuild\compiler-plugin.js:923:14)
at ImportScanner._scanFile (C:\tools\isobuild\import-scanner.js:849:14)
at each (C:\tools\isobuild\import-scanner.js:907:14)
at _.each._.forEach (C:\Users\holmesa\AppData\Local\.meteor\packages\meteor-tool\1.8.0\mt-os.windows.x86_64\dev_bundle\lib\node_modules\underscore\underscore.js:87:22)
at ImportScanner._scanFile (C:\tools\isobuild\import-scanner.js:871:5)
at each (C:\tools\isobuild\import-scanner.js:907:14)
at _.each._.forEach (C:\Users\holmesa\AppData\Local\.meteor\packages\meteor-tool\1.8.0\mt-os.windows.x86_64\dev_bundle\lib\node_modules\underscore\underscore.js:87:22) at ImportScanner._scanFile (C:\tools\isobuild\import-scanner.js:871:5)
at outputFiles.forEach.file (C:\tools\isobuild\import-scanner.js:529:14)
at Array.forEach (<anonymous>)
at ImportScanner.scanImports (C:\tools\isobuild\import-scanner.js:527:22)
at sourceBatches.forEach.batch (C:\tools\isobuild\compiler-plugin.js:1287:17)
at Array.forEach (<anonymous>)
at Function.computeJsOutputFilesMap (C:\tools\isobuild\compiler-plugin.js:1255:19)
at ClientTarget._emitResources (C:\tools\isobuild\bundler.js:1114:8)
at buildmessage.enterJob (C:\tools\isobuild\bundler.js:841:12)
at C:\tools\utils\buildmessage.js:359:18
at exports.EnvironmentVariable.withValue (C:\tools\utils\fiber-helpers.js:89:14)
at C:\tools\utils\buildmessage.js:352:34
at exports.EnvironmentVariable.withValue (C:\tools\utils\fiber-helpers.js:89:14)
at C:\tools\utils\buildmessage.js:350:23
at exports.EnvironmentVariable.withValue (C:\tools\utils\fiber-helpers.js:89:14)
at Object.enterJob (C:\tools\utils\buildmessage.js:324:26)
at ClientTarget.make (C:\tools\isobuild\bundler.js:829:18)
at C:\tools\isobuild\bundler.js:3115:14
at webArchs.forEach.arch (C:\tools\isobuild\bundler.js:3266:25)
at Array.forEach (<anonymous>)
at C:\tools\isobuild\bundler.js:3220:14
at C:\tools\utils\buildmessage.js:271:13
at exports.EnvironmentVariable.withValue (C:\tools\utils\fiber-helpers.js:89:14)
at C:\tools\utils\buildmessage.js:264:29
at exports.EnvironmentVariable.withValue (C:\tools\utils\fiber-helpers.js:89:14)
at C:\tools\utils\buildmessage.js:262:18
at exports.EnvironmentVariable.withValue (C:\tools\utils\fiber-helpers.js:89:14)
at C:\tools\utils\buildmessage.js:253:23
at exports.EnvironmentVariable.withValue (C:\tools\utils\fiber-helpers.js:89:14)
at Object.capture (C:\tools\utils\buildmessage.js:252:19)
at bundle (C:\tools\isobuild\bundler.js:3096:31)
at files.withCache (C:\tools\isobuild\bundler.js:3041:32)
at Object.withCache (C:\tools\fs\files.js:1712:12)
at Object.bundle (C:\tools\isobuild\bundler.js:3041:16)
at Profile.run (C:\tools\runners\run-app.js:569:24)
at Function.run (C:\tools\tool-env\profile.js:490:12)
at bundleApp (C:\tools\runners\run-app.js:568:34)
at AppRunner._runOnce (C:\tools\runners\run-app.js:610:35)
at AppRunner._fiber (C:\tools\runners\run-app.js:908:28)
at C:\tools\runners\run-app.js:398:12
I'm sure it's something I just did in the code, but the message isn't giving me enough to go on. Anyone know what this is?

Answer 1

Wow. Okay, I found the problem. It's this comma that should be a semicolon in an scss file.
See the red circle below. This innocuous typo causes the above error.