'Meteor build fails when run back to back

I'm trying to learn about the Meteor build process to improve it's performance for my dockerized Meteor app. I'm finding that if I run meteor build build --directory --server-only twice, back to back, I get an error about not being able to parse json on the second run.

Here's the successful first run:

 ❯❯❯ meteor build build --directory --server-only

WARNING: The output directory is under your source tree.
         Your generated files may get interpreted as source code!
         Consider building into a different directory instead
         meteor build ../output

WARNING: npm peer requirements (for juliancwirko:postcss) not installed:
 - [email protected] installed, postcss@^7.0.0 needed
 - [email protected] installed, postcss-load-config@^2.1.0 needed

Read more about installing npm peer dependencies:
  http://guide.meteor.com/using-packages.html#peer-npm-dependencies

   Minifying app stylesheet                  /
  Replace Autoprefixer browsers option to Browserslist config.
  Use browserslist key in package.json or .browserslistrc file.

  Using browsers option can cause errors. Browserslist config can
  be used for Babel, Autoprefixer, postcss-normalize and other tools.

  If you really need to use option, rename it to overrideBrowserslist.
                                                                                                                                                                                                              Learn more at:
  https://github.com/browserslist/browserslist#readme
  https://twitter.com/browserslist


Browserslist: caniuse-lite is outdated. Please run:
npx browserslist@latest --update-db
Why you should do it regularly:
https://github.com/browserslist/browserslist#browsers-data-updating
Browserslist: caniuse-lite is outdated. Please run:
npx browserslist@latest --update-db
   Minifying app code                        \

and here's the unsuccessful second run. Note that I didn't do anything inbetween runs:

 ❯❯❯ meteor build build --directory --server-only
WARNING: The output directory is under your source tree.
         Your generated files may get interpreted as source code!
         Consider building into a different directory instead
         meteor build ../output

WARNING: npm peer requirements (for juliancwirko:postcss) not installed:
 - [email protected] installed, postcss@^7.0.0 needed
 - [email protected] installed, postcss-load-config@^2.1.0 needed

Read more about installing npm peer dependencies:
  http://guide.meteor.com/using-packages.html#peer-npm-dependencies

/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/meteor-promise/promise_server.js:
218
      throw error;
      ^

SyntaxError: Unexpected token u in JSON at position 1
    at JSON.parse (<anonymous>)
    at /home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/tools/fs/tools/fs/optimistic.ts:321:17
    at wrap.makeCacheKey (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/tools/fs/tools/fs/optimistic.ts:36:
15)
    at recomputeNewValue (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/optimis
m/src/entry.ts:182:31)
    at Slot.withValue (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/@wry/conte
xt/lib/context.js:73:29)
    at reallyRecompute (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/optimism/
src/entry.ts:165:19)
    at Entry.recompute (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/optimism/
src/entry.ts:85:9)
    at optimistic (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/optimism/src/i
ndex.ts:101:25)
    at /home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/tools/fs/tools/fs/optimistic.ts:366:19
    at recomputeNewValue (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/optimis
m/src/entry.ts:182:31)
    at Slot.withValue (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/@wry/conte
xt/lib/context.js:73:29)
    at reallyRecompute (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/optimism/
src/entry.ts:165:19)
    at Entry.recompute (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/optimism/
src/entry.ts:85:9)
    at optimistic (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/optimism/src/i
ndex.ts:101:25)
    at find (/tools/isobuild/package-source.js:1339:30)
    at /tools/isobuild/package-source.js:1395:27
    at Array.forEach (<anonymous>)
    at find (/tools/isobuild/package-source.js:1374:22)
    at find (/tools/isobuild/package-source.js:1406:25)
    at /tools/isobuild/package-source.js:1395:27
    at Array.forEach (<anonymous>)
    at find (/tools/isobuild/package-source.js:1374:22)
    at /tools/isobuild/package-source.js:1395:27
    at Array.forEach (<anonymous>)
    at find (/tools/isobuild/package-source.js:1374:22)
    at /tools/isobuild/package-source.js:1395:27
    at Array.forEach (<anonymous>)
    at find (/tools/isobuild/package-source.js:1374:22)
    at /tools/isobuild/package-source.js:1395:27
    at Array.forEach (<anonymous>)
    at find (/tools/isobuild/package-source.js:1374:22)
    at /tools/isobuild/package-source.js:1395:27
    at Array.forEach (<anonymous>)
    at find (/tools/isobuild/package-source.js:1374:22)
    at /tools/isobuild/package-source.js:1418:34
    at Object.withCache (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/tools/fs/tools/fs/files.ts:1663:18)
    at PackageSource._findSources (/tools/isobuild/package-source.js:1418:18)
    at SourceArch.getFiles (/tools/isobuild/package-source.js:960:32)
    at /tools/isobuild/compiler.js:406:23
    at /tools/isobuild/compiler.js:186:28
    at Object.withCache (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/tools/fs/tools/fs/files.ts:1663:18)
    at /tools/isobuild/compiler.js:185:11
    at Function._.each._.forEach (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules
/underscore/underscore.js:186:9)
    at Object.compile (/tools/isobuild/compiler.js:180:5)
    at /tools/isobuild/bundler.js:3268:24
    at Object.capture (/tools/utils/buildmessage.js:283:5)
    at bundle (/tools/isobuild/bundler.js:3214:31)
    at /tools/isobuild/bundler.js:3157:32
    at Slot.withValue (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/@wry/conte
xt/lib/context.js:73:29)
    at Object.withCache (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/tools/fs/tools/fs/files.ts:1663:39)
    at Object.bundle (/tools/isobuild/bundler.js:3157:16)
    at buildCommand (/tools/cli/commands.js:1082:30)
    at /tools/cli/commands.js:945:25
    at Function.run (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/tools/tool-env/tools/tool-env/profile.ts
:289:14)
    at /tools/cli/commands.js:943:18
    at /home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/meteor-promise/fiber_pool.
js:43:40
 => awaited here:
    at Promise.await (/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/meteor-prom
ise/promise_server.js:60:12)
    at /tools/cli/main.js:1529:7

I've also tried doing the second run with a different directory output, but get the same result:

 ❯❯❯ meteor build .. --directory --server-only
WARNING: npm peer requirements (for juliancwirko:postcss) not installed:
 - [email protected] installed, postcss@^7.0.0 needed
 - [email protected] installed, postcss-load-config@^2.1.0 needed

Read more about installing npm peer dependencies:                                                                                                                                                             http://guide.meteor.com/using-packages.html#peer-npm-dependencies

/home/paymahn1/.meteor/packages/meteor-tool/.2.1.0.udr5f0.57lxg++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/meteor-promise/promise_server.js:
218
      throw error;
      ^
SyntaxError: Unexpected token u in JSON at position 1
    at JSON.parse (<anonymous>)

Why does meteor fail to build if I try to build it twice back to back?

meteor

Solution 1:^[1]

What happens is that you produce your built app but not bundle it (using the --directory flag).

Therefore you have extra JS files in your file structure.

And in your attempts, they are mixed with your Meteor project structure, in a build folder (when you use command meteor build build --directory) or directly merged (meteor build .. --directory).

Therefore, on the next build run, Meteor picks these extra JS files as if they were part of your source code (eager loading), and fails, as suggested in the warning message:

The output directory is under your source tree. Your generated files may get interpreted as source code! Consider building into a different directory instead meteor build ../output

It would have worked in your next attempt if you had specified an explicit sibling build folder, instead of just the parent folder (which therefore puts files directly in your Meteor project root), e.g. meteor build ../siblingFolder

Another possible workaround is to use a build folder name starting with a dot ., so that Meteor ignores it on the next runs when it looks for source code, e.g. meteor build ./.build

See special directories docs:

The following directories are also not loaded as part of your app code:

Files/directories whose names start with a dot, like .meteor and .git

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1	ghybs

'Meteor build fails when run back to back

Solution 1:[1]

Sources

Related Questions

Solution 1:^[1]