Flow: Internal error: merge job timed out after xxx seconds

[bokuweb]

Internal error: merge job timed out after xxx seconds error occurred. But other error looks correct.
This error appears v0.63.0~, but v0.62.0 works fine in my project (I can not provide this project because it is private...). I can not know how to reproduce this error.

Can I set merge timeout value to avoid timeout?

[osmestad]

We had the same issue, you can set 'merge_timeout' either in your .flowconfig or as a command line flag. That helped for us :-)

[bokuweb]

@osmestad Thanks :) I'll try it!

[IanLondon]

@bokuweb did setting a higher timeout fix the problem for you? I'm having the same issue.

[bokuweb]

@osmestad Hi :). I increased timeout, but it did not solve it..

[IanLondon]

For me, I found out the problem was that flow was getting stuck inferring the type of an accumulator in a reduce operation. It took a long time using trial & error to narrow it down, but once I added a type annotation to the accumulator in the reduce callback, the merge operation completed in a reasonable time. Hope that helps.

[osmestad]

For us I suspect the types may have had a circular dependency, but I have not tried to reduce a test case of it (simplifying the code some seemed to help the speed, was only happening on the build server for us so painful to isolate). Looking at the Flow logs might also be useful, as that gives a bit more info than the console output :-)

[rostislav-simonik]

I've the same problem. Is there any profiling option that I can use to narrow area of issue. I've large project and it took 34 seconds before. Now it takes ~ 1500 seconds.

[frontendphil]

I'm usually not a fan of "me too" posts, but well me too! Today the flow check stopped working for no apparent reason. I've already added type definitions to the recursive methods I've found but that didn't help. If I use flow check-contents it works but takes forever... I'm out of ideas on how I can fix that.

[kogai]

The same error occurred at 0.86 👀

I don't know it's worth or not, server log of Flow like below.

(8650) merge_strict_job THROWS: [35] `A file path which Flow reported to merge job timeout occurred`
      `blah, blah, blah...`
Flow_error.EMergeTimeout(105.011678934)
Raised by primitive operation at file "src/typing/flow_js.ml", line 11123, characters 21-55
Called from file "src/typing/flow_js.ml", line 8504, characters 4-28

[kogai]

Still causing at 0.87 👀
I haven't idea whether it causes by a bug of Flow or any mistake in my code 🤔

[Maggie199]

Still causing at 0.93

[nebakry]

Reinstalling packages helped me in my case