Attempting to build the same project with LDC 1.25.1 vs 1.26.0-beta1 results in a linker error

[GavinRay97]

The strange thing is that the file it says doesn't exist, actually does, and there are no permissions issues.

Maybe a problem with the length of the directory name in total?

1.25.1

1.26.0-beta1

Here's a video of me deleting the dub packages appdata folder and rebuilding, and showing that the file does indeed exist where it says it doesn't (both with ls and visually):

ZZs1va5j36.mp4

Hope this is useful -- thank you! =)

[kinke]

Hi,

Maybe a problem with the length of the directory name in total?

Yes, most likely the 6 additional -beta1 chars pushing it over the limit; we've just had similar Windows long-path issues with dub at work. If link.exe doesn't support the \\?\ prefix for paths > 260 chars, there's nothing LDC can do.

[GavinRay97]

Ouch.

Let me do some more testing on this. I googled, and there's a registry value LongPathsEnabled which disables the 260 character path limit:

https://www.howtogeek.com/266621/how-to-make-windows-10-accept-file-paths-over-260-characters/

I went to set this value to 1, but found it was already set to that:

So it can't be that 🤔

Let me try to build some other programs, or see if I can somehow narrow down what is causing this.
Any tips for debugging root cause of this -- or is this not even a LDC issue, but rather a link.exe one?

Thank you for all your hard work, it's much appreciated =)

[GavinRay97]

Ah, once you mentioned the LINK.exe thing, I tried this in dub.json:

{
  "dflags": ["-linker=lld-link"],
}

Problem gone. Superior LLVM toolchain saves the day -- lld is faster & has better errors anyways! 😅
Should have thought of that earlier.

I'm not sure if I would consider it solved ha, but it's not longer a problem at least 👍

[kinke]

I've hit this again (with a path significantly shorter than 260 chars); link.exe does support \\?\ prefixes, so LDC could accommodate for the ridiculous MS linker limitation (edit: nope, it doesn't). Unfortunately, that still wouldn't prevent dub from superfluously rebuilding such projects every time: dlang/dub#2143

[kinke]

With dlang/dub#2144 and #3756, the bundled dub now supports paths up to 260 chars (absolute, normalized), independent from the current working directory when invoking dub. I expect this to fix almost all cases. As the MS linker doesn't support longer paths, we cannot do anything from the LDC side - we already have -link-internally and -linker=lld-link etc.