[FFmpeg-devel] [PATCH] build: fix make checkheaders in out-of-tree builds

[Hendrik Leppkes]

On Mon, Jan 25, 2016 at 2:34 AM, Andreas Cadhalpun
<andreas.cadhalpun at googlemail.com> wrote:
> On 24.01.2016 22:57, Hendrik Leppkes wrote:
>> While links are in theory a good idea, creating directory links on
>> windows requires elevated privileges. Don't ask me why, I don't know,
>> but that makes this unfortunately impractical.
>> Copying files around between different physical media is not a
>> solution, but an ugly hack and a build performance regression. See
>> earlier point about re-opening the review phase of this change to
>> discuss such "solutions".
>
> Oh well, MSVC just doesn't want this to work...
>
> Then let's do it the other way around: create a link from the destination
> path to the source path.
> If that link can be created, it can be used as relative path and otherwise
> one can still use the full source path.
>
> Attached is a patch implementing this.
> It should not be possible that this breaks anywhere.
>
> Feel free to apply this if it makes MSVC builds work again.
>

msys doesn't seem to like creating directory symlinks with ln -s, for
some reason it copies the folder instead, which is of course terribly
slow.
Could try to use the windows link creating function, but thats
probably too much trouble.

If we already have a way to fallback to the "old way", maybe this
could be put under a OS conditional, ie. exclude msys/cygwin?

- Hendrik