Posted on Jul 2, 2021

Fixing FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory in Webpacker

Purpose

The purpose of this is to remind myself what to do next time I encounter this error with Webpacker.

The error

Heres the full error I was receiving when running ./bin/webpack-dev-server, no I have no idea how it got into this state. It also persisted in this state through multiple machine resets and I wrangled with this for over an hour.

➜ veue git:(VEUE-950) ./bin/webpack-dev-server ℹ ｢wds｣: Project is running at http://localhost:3035/ ℹ ｢wds｣: webpack output is served from /packs/ ℹ ｢wds｣: Content not from webpack is served from /Users/konnorrogers/projects/veue-live/veue/public/packs ℹ ｢wds｣: 404s will fallback to /index.html<--- Last few GCs --->[28586:0x118008000] 30682 ms: Scavenge 2033.1 (2042.8) -> 2030.5 (2043.8) MB, 3.8 / 0.0 ms (average mu = 0.348, current mu = 0.382) allocation failure [28586:0x118008000] 30696 ms: Scavenge 2034.2 (2043.8) -> 2031.7 (2045.0) MB, 4.0 / 0.0 ms (average mu = 0.348, current mu = 0.382) allocation failure [28586:0x118008000] 30707 ms: Scavenge 2035.3 (2053.0) -> 2032.8 (2054.5) MB, 3.6 / 0.0 ms (average mu = 0.348, current mu = 0.382) allocation failure<--- JS stacktrace --->FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory  1: 0x10130c5e5 node::Abort() (.cold.1) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 2: 0x1000b2289 node::Abort() [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 3: 0x1000b23ef node::OnFatalError(char const*, char const*) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 4: 0x1001f68c7 v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, bool) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 5: 0x1001f6863 v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, bool) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 6: 0x1003a47e5 v8::internal::Heap::FatalProcessOutOfMemory(char const*) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 7: 0x1003a628a v8::internal::Heap::RecomputeLimits(v8::internal::GarbageCollector) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 8: 0x1003a19b5 v8::internal::Heap::PerformGarbageCollection(v8::internal::GarbageCollector, v8::GCCallbackFlags) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 9: 0x10039f2e0 v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 10: 0x10039e248 v8::internal::Heap::HandleGCRequest() [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 11: 0x10035a6e1 v8::internal::StackGuard::HandleInterrupts() [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 12: 0x1006fb197 v8::internal::Runtime_StackGuardWithGap(int, unsigned long*, v8::internal::Isolate*) [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 13: 0x100a81a79 Builtins_CEntry_Return1_DontSaveFPRegs_ArgvOnStack_NoBuiltinExit [/Users/konnorrogers/.asdf/installs/nodejs/14.17.2/bin/node] 14: 0xb84c93c8ef3 [1] 28586 abort ./bin/webpack-dev-server

Possible fixes

https://stackoverflow.com/questions/38855004/webpack-sass-maximum-call-stack-size-exceeded

This stack overflow posts recommends a couple fixes including settings the max stack size. No dice. Still didnt work. I tried a number of other node specific fixes. Nothing.

Is it a caching issue? Yes. Its probably a caching issue.

So what was the fix then? Remove the cache. Webpacker internally stores a cache in tmp/cache/webpacker for faster reading / writing operations so it doesnt have to fully bundle all your assets and uses the cache to speed things up.

Because I was quite annoyed by this point, I just nuked the whole thing.