[vcpkg] Add vcpkg_from_sourceforge (1/2)

[JackBoosY]

There are 43 ports in vcpkg downloaded using sourceforge.
Adding a unified download method is convenient for modifying the download method of the sourceforge storage port in the future.

Related: #11502.

• Add function vcpkg_from_sourceforge
• Modify all ports involved in download
• Add documentation

[JackBoosY]

@Neumann-A @voskrese @cenit Could you please review this PR?

Thanks.

[cenit]

apart from one single note, it's a very nice addition IMHO.
Thanks @JackBoosY

[JackBoosY]

In the next PR, I will add code to retry different mirrors in this function.

[strega-nil]

That's the only things I see; I would still like to see moving from regex to substring, and printing an error if there's more than one /

[strega-nil]

Thanks JacK!

[strega-nil]

What are the blockers to merging this? Just CI running?

[vicroms]

Just CI

[BillyONeal]

Yeah, for some reason the previous attempt broke inside Azure Pipelines (some of the machines dropped off the face of the earth)

[strega-nil]

Cool :)

[c72578]

In case of pcre2, the primary download server was:
https://ftp.pcre.org/pub/pcre/
This has been removed here by switching to vcpkg_from_sourceforge().
The following appears now in artifacts of failed CI-builds [1]:

-- Downloading https://downloads.sourceforge.net/project/pcre/pcre2/10.30/pcre2-10.30.zip... Failed. Status: 7;"Couldn't connect to server"

During the CI-build of commit a0bd59c it occurred two times (pcre2:x64-windows and pcre2:x64-uwp).
Is there a possibility to have a different download server like https://ftp.pcre.org/pub/pcre/ also when using vcpkg_from_sourceforge()? Otherwise the previous vcpkg_download_distfile() used for pcre2 would be more reliable.

[1] https://dev.azure.com/vcpkg/public/_build/results?buildId=39415&view=results

[JackBoosY]

I will take a look later. Thank's for notice that.

[JackBoosY]

@c72578 Try to downloads source with all mirrors has been added in my other PR #12018. You can try that.

[c72578]

@JackBoosY Thanks. The PR #12018 can improve the situation concerning downloads from sourceforge and sourceforge mirrors. However, it does not compensate the removal of different, independent download sources like https://ftp.pcre.org/pub/pcre/ etc.

[BillyONeal]

@c72578 Does #12233 do what you want?

[c72578]

@BillyONeal, yes #12233 LGTM. It primarily uses the original download server and as an alternative possibility the improved download from sourceforge.