Reversing use_bzip2

[Ryan Schmidt]

On Sep 13, 2017, at 08:42, Rainer Müller wrote:

> On 2017-09-13 11:48, Mojca Miklavec wrote:
>> When trying to update x86_64-w64-mingw32-gcc I noticed that GCC 7.2 no
>> longer provides bzip2 sources, but I'm not sure how to tell the
>> Portfile that it should use xz instead of bzip2 given that the
>> crossgcc group already contains "use_bzip2 yes".
> Normally, this would be as simple as 'use_xz yes' in the Portfile to
> override the 'use_bzip2 yes' of the PortGroup. [...]

I haven't had a great deal of success with that myself. It seems to me that currently a port (and any portgroups it includes) should use at most one of the compression format options (use_bzip2, use_xz, etc.) and only set it to yes, and not attempt to set it to no and change it later.