@next runs out of memory on build, throws JS stacktracke

[hyperknot]

I'm getting this one with @next branch. I'm using:

npx create-react-app@next --scripts-version=2.0.0-next.3e165448 app-name

<--- Last few GCs --->

[74687:0x103000000]    80393 ms: Mark-sweep 1364.8 (1460.4) -> 1364.6 (1463.4) MB, 1038.8 / 0.0 ms  allocation failure GC in old space requested
[74687:0x103000000]    81325 ms: Mark-sweep 1364.6 (1463.4) -> 1364.4 (1429.9) MB, 931.1 / 0.0 ms  last resort GC in old space requested
[74687:0x103000000]    82266 ms: Mark-sweep 1364.4 (1429.9) -> 1364.4 (1426.9) MB, 940.7 / 0.0 ms  last resort GC in old space requested


<--- JS stacktrace --->

==== JS stack trace =========================================

Security context: 0x13240d025879 <JSObject>
    1: _parseMappings(aka SourceMapConsumer_parseMappings) [/Users/user/nonsync/dev/populus/groundtruth/fe/build/node_modules/webpack-sources/node_modules/source-map/lib/source-map-consumer.js:~468] [pc=0x1a0d2022cd16](this=0x13244ecf6989 <BasicSourceMapConsumer map = 0x13240e45fe21>,aStr=0x13245a582201 <Very long string[6486484]>,aSourceRoot=0x13244ecf6ce1 <String[50]: /Users/user/nonsync/dev/p...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory
 1: node::Abort() [/Users/user/n/bin/node]
 2: node::FatalException(v8::Isolate*, v8::Local<v8::Value>, v8::Local<v8::Message>) [/Users/user/n/bin/node]
 3: v8::internal::V8::FatalProcessOutOfMemory(char const*, bool) [/Users/user/n/bin/node]
 4: v8::internal::Factory::NewFixedArray(int, v8::internal::PretenureFlag) [/Users/user/n/bin/node]
 5: v8::internal::HashTable<v8::internal::NameDictionary, v8::internal::NameDictionaryShape>::EnsureCapacity(v8::internal::Handle<v8::internal::NameDictionary>, int, v8::internal::PretenureFlag) [/Users/user/n/bin/node]
 6: v8::internal::Dictionary<v8::internal::NameDictionary, v8::internal::NameDictionaryShape>::Add(v8::internal::Handle<v8::internal::NameDictionary>, v8::internal::Handle<v8::internal::Name>, v8::internal::Handle<v8::internal::Object>, v8::internal::PropertyDetails, int*) [/Users/user/n/bin/node]
 7: v8::internal::LookupIterator::ApplyTransitionToDataProperty(v8::internal::Handle<v8::internal::JSObject>) [/Users/user/n/bin/node]
 8: v8::internal::Object::AddDataProperty(v8::internal::LookupIterator*, v8::internal::Handle<v8::internal::Object>, v8::internal::PropertyAttributes, v8::internal::Object::ShouldThrow, v8::internal::Object::StoreFromKeyed) [/Users/user/n/bin/node]
 9: v8::internal::Runtime_SetProperty(int, v8::internal::Object**, v8::internal::Isolate*) [/Users/user/n/bin/node]
10: 0x1a0d1fa842fd
11: 0x1a0d2022cd16
12: 0x1a0d1fcf6ee2
error Command failed with signal "SIGABRT".

[hyperknot]

It goes up to 1.36 GB of memory usage before terminating.

[hyperknot]

I've run into critical issues with next.

• Bundle size is 2x compared to 1.x.
• Runs into 1.4 GB memory issue and then terminates
• If I disable source map and minification so that it finally builds, the build takes 144 sec vs. 36 sec for 1.x

=> I'd consider @next branch to be unusable as of today and I've reverted everything to 1.x.

[hyperknot]

I think it might be because of UglifyJsPlugin / uglifyjs-webpack-plugin.

I can replicate it on 1.x by using UglifyJsPlugin + options from 2.x, even with a mangle-only config:

new UglifyJsPlugin({
      uglifyOptions: {
        parse: {
          // we want uglify-js to parse ecma 8 code. However, we don't want it
          // to apply any minfication steps that turns valid ecma 5 code
          // into invalid ecma 5 code. This is why the 'compress' and 'output'
          // sections only apply transformations that are ecma 5 safe
          // https://github.com/facebook/create-react-app/pull/4234
          ecma: 8,
        },
        compress: false,
        mangle: {
          safari10: true,
        },
        output: {
          ecma: 5,
          comments: false,
          // Turned on because emoji and regex is not minified properly using default
          // https://github.com/facebook/create-react-app/issues/2488
          ascii_only: true,
        },
      },
      // Use multi-process parallel running to improve the build speed
      // Default number of concurrent runs: os.cpus().length - 1
      parallel: true,
      // Enable file caching
      cache: true,
      sourceMap: shouldUseSourceMap,
    }),

[SPAHI4]

I can't specify the version, but since one of the last npm @next releases, it does the same for me.

after overriding UglifyJsPlugin options with sourceMap: false it works

[bugzpodder]

There is a GENERATE_SOURCEMAP option on the CI env variable that you can disable when building:
https://github.com/facebook/create-react-app/blob/69c3d4b04c233ba9fb9d16691056bd09076177b1/packages/react-scripts/template/README.md#advanced-configuration

[hyperknot]

The issue is that @next is using significantly more memory and is much slower compared to 1.x, even with identical Uglifyjs plugin.

[Timer]

@hyperknot can you please subscribe to #5024 and test the next v2 beta when it comes out? It should be soon.

[stale]

This issue has been automatically marked as stale because it has not had any recent activity. It will be closed in 7 days if no further activity occurs.