add a note on how long it takes to build julia on WSL

[lawless-m]

There was a thread on Discourse about how this looks like it has stopped working

https://discourse.julialang.org/t/installing-julia-from-source-on-wsl-halts-for-an-infinite-time/77923

I tried it myself and it sat at 100% CPU with no output on the console for over an hour, but it did eventually finish.

It was suggested by the original poster to add a note, which I think is reasonable.

[staticfloat]

It should definitely not take over an hour without printing anything to the console. The last linking step should take a while, but maybe 1-2 minutes at most. What kind of a computer are you running this on?

[lawless-m]

Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: Intel(R) Core(TM) i5-7200U CPU @ 2.50GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, skylake)

[Saransh-cpp]

I can confirm this. As suggested by @lawless-m on discourse, I kept the build running for about an hour and it eventually finished.

• Windows 64 bit
• intel i5 10300H (4 cores) @ 2.50GHz
• Running on Ubuntu-20.04 in WSL2

[staticfloat]

Alright, this definitely feels like a WSL2-specific issue, as on a similar machine on native Windows or Linux, the same step takes only 1-2 minutes. Perhaps change the note to say On WSL, this can take up to an hour.

[lawless-m]

The note is already in the WSL based installation instructions, not the general ones.

[KristofferC]

Would be good for someone else to confirm that this is indeed a WSL2 problem and not just some local artifact.

[fredrikekre]

The note is already in the WSL based installation instructions, not the general ones.

Is it? Seems to be under the header: ### Cross-compiling from Unix (Linux/Mac/WSL)

[lawless-m]

Oh, my mistake, yes I should have made it more clear

[musm]

Hmm this feels like a WSL2 specific issue. I'll try it out later on my end.

[KristofferC]

It took 5 minutes for me from make clean to finish building on WSL2 so I think this is some local problem.