error: PCH file uses an older PCH format that is no longer supported

[beyondpie]

Describe the bug
Using cmdstanr::cmdstan_model compile model faces the error:
PCH file uses an older PCH format that is no longer supported

Operating system
Mac OS 10.15.7

CmdStanR version number
0.1.3

[beyondpie]

This program is workable on Linux Ubuntu when I use the same function.

[beyondpie]

stan-dev/cmdstanpy#108
I notice a related issue in cmdstanpy. But I didn't get any hints there.

[jgabry]

Hmm, can you try running rebuild_cmdstan() and then see if the error persists?

[beyondpie]

@jgabry
Interesting! It now works! Thank you!

[rok-cesnovar]

This is an issue that pops up on macOS sometimes when xcode upgrades. I think it happens often enough that we should try to catch this error message and signal to the user that rebuild_cmdstan() is the solution.

Weirdly this does not pop up on Linux if I upgrade the clang compiler.

I am going to reopen this and we can close this once we have a way to suggest to the user to rebuild cmdstan.

[mitzimorris]

I've hit this a couple of times and added a mention specifically of PCH files in the CmdStan doc. as the docs are not a very good solution, I like Rok's suggestion of trying to catch the error message and do the right thing.

[jgabry]

@beyondpie glad it's working now. @rok-cesnovar @mitzimorris Yeah it would be great to catch this error.

[beyondpie]

One strange thing is:

• I use cmdstanr to install the newest cmdstan (2.25.0)
• then I compile a stan model, it's OK.
• and I modified the model. cmdstan report bugs in the model.
• I correct it. Then compile the model. It says PCH file uses an older PCH format.
• I have to use rebuild_cmdstan(), then it works.

But during this process, I didn't update my Xcode or Mac system...

[rok-cesnovar]

So this happens every time? Or just once and now it will work?

Do you use any compile flags like stan_threads?

[beyondpie]

@rok-cesnovar

• I don't use any compile flags (though in the future, I plan to use GPU support...)
• I modified the stan script, it happens again. (but not every time. I happen to face this twice, but now it seems OK ... )
• BTW, I use cmdstanr::cmdstan_model( my_stan_file, compile = T ) to compile the model. I notice there is a arg force_recompile = FALSE. I try to set it as T, but it's not useful.

One more details:

• when I have a successful compiled stan model
• then I update the stan script, and try to compile again (before compiling, I remove the old compiled one)
• error: PCH file uses a newer PCH format that cannot be read

[beyondpie]

I don't know the details. But seems there is some cache during compiling ? And only when I rebuild_cmdstan(), the cache is cleared?

[mitzimorris]

then I update the stan script, and try to compile again

by script you mean the model.stan file?
every time you update a Stan program and recompile, you get this error?

perhaps problem with the Makefile?