Memory leak / JavaScript heap out of memory

[IlyaSemenov]

I get this (or similar) every few hours of running ream dev:

<--- Last few GCs --->

[11102:0x105000000] 22881587 ms: Mark-sweep 1379.7 (1426.5) -> 1379.6 (1429.0) MB, 520.9 / 0.0 ms  allocation failure GC in old space requested
[11102:0x105000000] 22882282 ms: Mark-sweep 1379.6 (1429.0) -> 1379.6 (1411.0) MB, 694.6 / 0.0 ms  last resort GC in old space requested
[11102:0x105000000] 22882916 ms: Mark-sweep 1379.6 (1411.0) -> 1379.6 (1411.0) MB, 634.6 / 0.0 ms  last resort GC in old space requested


<--- JS stacktrace --->

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

    0: ExitFrame [pc: 0x38888d80427d]
Security context: 0x168246620769 <JSObject>
    1: fromString(aka fromString) [buffer.js:349] [bytecode=0x1682cccd5a81 offset=148](this=0x1682db2822e1 <undefined>,string=0x1682f8ec0671 <Very long string[2015095]>,encoding=0x168246632879 <String[4]: utf8>)
    2: from [buffer.js:201] [bytecode=0x1682cccd5601 offset=11](this=0x168279046b39 <JSFunction Buffer (sfi = 0x168206f0a441)>,value=0x1682f8ec0671 ...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory
 1: node::Abort() [/usr/local/Cellar/node/10.3.0/bin/node]
 2: node::OnFatalError(char const*, char const*) [/usr/local/Cellar/node/10.3.0/bin/node]
 3: v8::Utils::ReportOOMFailure(char const*, bool) [/usr/local/Cellar/node/10.3.0/bin/node]
 4: v8::internal::V8::FatalProcessOutOfMemory(char const*, bool) [/usr/local/Cellar/node/10.3.0/bin/node]
 5: v8::internal::Factory::NewRawTwoByteString(int, v8::internal::PretenureFlag) [/usr/local/Cellar/node/10.3.0/bin/node]
 6: v8::internal::String::SlowFlatten(v8::internal::Handle<v8::internal::ConsString>, v8::internal::PretenureFlag) [/usr/local/Cellar/node/10.3.0/bin/node]
 7: v8::String::WriteUtf8(char*, int, int*, int) const [/usr/local/Cellar/node/10.3.0/bin/node]
 8: node::StringBytes::Write(v8::Isolate*, char*, unsigned long, v8::Local<v8::Value>, node::encoding, int*) [/usr/local/Cellar/node/10.3.0/bin/node]
 9: node::Buffer::New(v8::Isolate*, v8::Local<v8::String>, node::encoding) [/usr/local/Cellar/node/10.3.0/bin/node]
10: node::Buffer::(anonymous namespace)::CreateFromString(v8::FunctionCallbackInfo<v8::Value> const&) [/usr/local/Cellar/node/10.3.0/bin/node]
11: v8::internal::FunctionCallbackArguments::Call(v8::internal::CallHandlerInfo*) [/usr/local/Cellar/node/10.3.0/bin/node]
12: v8::internal::MaybeHandle<v8::internal::Object> v8::internal::(anonymous namespace)::HandleApiCallHelper<false>(v8::internal::Isolate*, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::FunctionTemplateInfo>, v8::internal::Handle<v8::internal::Object>, v8::internal::BuiltinArguments) [/usr/local/Cellar/node/10.3.0/bin/node]
13: v8::internal::Builtin_Impl_HandleApiCall(v8::internal::BuiltinArguments, v8::internal::Isolate*) [/usr/local/Cellar/node/10.3.0/bin/node]
14: 0x38888d80427d
15: 0x38888d8144f7
16: 0x38888d8144f7
17: 0x38888d80cac3
18: 0x38888d8144f7
19: 0x38888d80cac3
20: 0x38888d8144f7
21: 0x38888d8144f7
error Command failed with signal "SIGABRT".

I have never seen anything similar on any other Node.js project (including vue-cli or nuxt). I tried upgrading from Node 10.0 to Node 10.3 and it made no difference.

I understand that unless you can repeat this, there's not much use of this report. I wanted to leave it there just in case if other people start getting this too, we could at least boldly confirm the issue, or even coordinate somehow.

[IlyaSemenov]

This time I got some stack trace:

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

    0: ExitFrame [pc: 0x29853c38427d]
Security context: 0x358f75020769 <JSObject>
    1: update [internal/crypto/hash.js:62] [bytecode=0x358f1e3df281 offset=106](this=0x358fa0ae20d9 <Hash map = 0x358fe61fa341>,data=0x358fa0ae2071 <Very long string[2323448]>,encoding=0x358f7e9822e1 <undefined>)
    2: update [/Users/semenov/work/xxx/node_modules/webpack/lib/util/createHash.js:25] [bytecode=0x358f1e3decf1 offset=85](this...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory
 1: node::Abort() [/usr/local/Cellar/node/10.3.0/bin/node]
 2: node::OnFatalError(char const*, char const*) [/usr/local/Cellar/node/10.3.0/bin/node]
....
`

[IlyaSemenov]

Another one:

    0: ExitFrame [pc: 0x2a56ba78427d]
    1: StubFrame [pc: 0x2a56ba808360]
Security context: 0x22eeadca0769 <JSObject>
    2: _parseMappings(aka SourceMapConsumer_parseMappings) [/Users/semenov/work/xxx/node_modules/webpack-sources/node_modules/source-map/lib/source-map-consumer.js:508] [bytecode=0x22ee46ee6cc1 offset=187](this=0x22ee05579621 <BasicSourceMapConsumer map = 0x22eed998de71>,aStr=0x22ee05579601 <String[5]...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory

[IlyaSemenov]

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

Security context: 0x1e5d241a0769 <JSObject>
    0: builtin exit frame: parse(this=0x1e5d241886a9 <Object map = 0x1e5d49802ac1>,0x1e5d80c02201 <Very long string[2619810]>,0x1e5d241886a9 <Object map = 0x1e5d49802ac1>)

    1: handler [/Users/semenov/work/xxx/node_modules/ream/lib/utils/setupWebpackMiddlewares.js:~26] [pc=0xf3159aab322](this=0x1e5dbc64ad09 <Watching map = 0x1e5de4d142c1>,err=0x1e5d68102201 <null>)
    2: ...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory
 1: node::Abort() [/usr/local/Cellar/node/10.3.0/bin/node]
 2: node::OnFatalError(char const*, char const*) [/usr/local/Cellar/node/10.3.0/bin/node]
 3: v8::Utils::ReportOOMFailure(char const*, bool) [/usr/local/Cellar/node/10.3.0/bin/node]
 4: v8::internal::V8::FatalProcessOutOfMemory(char const*, bool) [/usr/local/Cellar/node/10.3.0/bin/node]
 5: v8::internal::Factory::NewRawTwoByteString(int, v8::internal::PretenureFlag) [/usr/local/Cellar/node/10.3.0/bin/node]

[IlyaSemenov]

Just wanted to update that it happens not only on OS X but also on Ubuntu. It might be related to a specific webpack plugin though. I'll be converting an another project to Ream soon and will see if this repeats.