github portgroup: possible worksrcdir mismatch for ports with `github.tarball_from archive`

[yan12125 (Chih-Hsuan Yen)]

For example, in port py-curl, I use the following lines to utilize the github portgroup:

github.setup        pycurl pycurl 7_43_0_3 REL_
github.tarball_from archive

In the downloaded tarball, the top level directory is pycurl-REL_7_43_0_3, while the value of worksrcdir, which is set to distname as usual, is ${github.project}-${github.version}, or pycurl-7_43_0_3 (REL_ prefix is gone). For MacPorts 2.5.4, such a mismatch leads to build failures like (1). For MacPorts git-master, building py-curl is OK as a symlink will be created in certain scenarios (2). I consider (2) a workaround, and worksrcdir should be fixed in the github portgroup. A possible solution is using worksrcdir ${github.project}-${git.branch} for ports using github.tarball_from archive.

(1) ​https://build.macports.org/builders/ports-10.14_x86_64-builder/builds/33145/steps/install-port/logs/stdio

(2) ​https://github.com/macports/macports-base/pull/55

[mascguy (Christopher Nielsen)]

Assigning to Ryan, as he's in the process of fixing:

​https://github.com/macports/macports-ports/commit/c9d43d56b90a7a10090ca07d92052b7196e986c8#r69982428

[mascguy (Christopher Nielsen)]

Add keyword portgroup, to pg-related tickets