Freeze when compiling "after a while"

1

I’m not yet sure how to reliably reproduce this.

The observation is that at beginning of my coding sessions, when I start the compilation like below:

$ rescript clean -with-deps && rescript build -w
>>>> Start compiling
rescript: [46/46] src/resolvers/Resolver.cmj # this is where it freezes
>>>> Finish compiling 90494 mseconds

My machine will freeze for 1-2 minutes. I suspect this might have something to do with a lot of file watchers and a lot of write, but as I cannot reliably reproduce this after these “first compilation daily”, I’m not sure yet what could be the case.

2

can you run bstracing after the build to see which part takes particularly long time?

3

Okay, so I am able to kinda reproduce the issue. It happens after I switch between branches with git

When I run bstracing after running rescript build -w, everything seems to be stretched for the whole duration of the compilation (Wall Duration is approximately the same for every row, or “process”).

When I run bstracing after running rescript build, some processes took much longer. They are stuck at the cmj category.

Should I provide better details somehow?

4

Now I also observed lag in cmi category.

It’s also not just rescript build that can freeze. Sometimes rescript does not freeze but after that git would freeze when I try to checkout other commits.

5

Do you find which one takes particularly long time ?

6

Some span took really long, for example:

Title Database.cmj,Database.bs.js :mag:
Category cmj
User Friendly Category other
Start 269.000 ms
Wall Duration 45,143.000 ms

Sorry I’m not too familiar with this tool so I don’t know what to report.

And it doesn’t just take long doing its own thing, but my whole computer freezes while it is doing stuffs (BigSur 11.2.3).

7

What is in side database? Does it have some pathological pattern? Is it generated code?
Can you reproduce it by touch database module