> On 11 Dec 2021, at 10:42 pm, Jason Liu <jason...@umich.edu> wrote:
>
>
>> On Sat, Dec 11, 2021 at 5:20 PM Ryan Schmidt <ryandes...@macports.org> wrote:
>>
>>
>>> On Dec 10, 2021, at 15:07, Jason Liu wrote:
>>>
>>> A conversation in one of my PRs has brought up an interesting question that
>>> I've been wondering about for a long time. In Portfiles, whenever I've had
>>> a test for `${os.major} <= xx`, I've typically always added an additional
>>> check for darwin in the front, i.e.:
>>>
>>> if {${os.platform} eq "darwin" && ${os.major} <= xx} {
>>>
>>> I've done it that way because I basically copied what I saw from other
>>> Portfiles, and because I get gently admonished by the committers when I
>>> forget to.
>>
>> Yes, please always do that.
>
>
> Then would it be easier (or even kosher) to simply wrap the majority of the
> Portfile inside of a single
>
> if {${os.platform} eq "darwin"} {
>
> and be done with it, instead of needing to add one each and every time I have
> a conditional involving `${os.major}`?
No, because that would render the port non functional on non darwin OSes. You
should only specify the darwin platform when it is actually required, e.g. when
then making a os.major conditional that inly makes sense in darwin platforms.
So basically, following the recommendations as currently given.
Chris
>
>>> I was under the impression that the `platforms darwin` line means that the
>>> entire Portfile is supposed to be valid only for `${os.platform} eq
>>> "darwin"`, no? (In other words, my understanding is that a line such as
>>> `platforms darwin freebsd openbsd` is meant to signify that "this Portfile
>>> is supposed to be valid for the listed platforms".) If that's not the case,
>>> then what is the purpose of `platforms darwin`?
>>
>> The platforms line is not used by MacPorts in any way at this time, other
>> than to display it in the output of "port info". There is a ticket about
>> possibly using it in the future as a way to indicate which OS versions the
>> port is compatible with, but I don't think that got beyond the idea phase.
>
> That seems like a pity, and a bit of a waste, considering that platforms is
> being included in each and every Portfile.
>
> --
> Jason Liu
>
>
>> On Sat, Dec 11, 2021 at 5:20 PM Ryan Schmidt <ryandes...@macports.org> wrote:
>>
>>
>> On Dec 10, 2021, at 15:07, Jason Liu wrote:
>>
>> > A conversation in one of my PRs has brought up an interesting question
>> > that I've been wondering about for a long time. In Portfiles, whenever
>> > I've had a test for `${os.major} <= xx`, I've typically always added an
>> > additional check for darwin in the front, i.e.:
>> >
>> > if {${os.platform} eq "darwin" && ${os.major} <= xx} {
>> >
>> > I've done it that way because I basically copied what I saw from other
>> > Portfiles, and because I get gently admonished by the committers when I
>> > forget to.
>>
>> Yes, please always do that.
>>
>>
>> > But I've also always wondered why it's necessary.
>>
>> Your Portfile could be parsed or accessed by non-Darwin operating systems.
>> For example, before we took over server hosting duties in 2016, all of the
>> server VMs including the one that generated the PortIndex files (except the
>> actual macOS build machines) were running Linux; perhaps some day we will
>> once again want to try using a server OS other than macOS for this task.
>> There are even some users using Linux to test various things in MacPorts. We
>> don't really expect many ports to be installable on other operating systems
>> or for maintainers to test anything on other operating systems, but just
>> take 2 seconds when you're writing an OS version conditional to think about
>> what you're trying to express, and then express it, including checking
>> os.platform. Typical forms include the one you mentioned:
>>
>> if {${os.platform} eq "darwin" && ${os.major} <= xx}
>>
>> (<, <=, ==, >=, >)
>>
>> And the other one:
>>
>> if {${os.platform} ne "darwin" || ${os.major} <= xx}
>>
>> (<, <=, ==, >=, >)
>>
>> Usually the decision about which to use comes down to whether the thing
>> you're doing is Mac-specific or not. For example, if you were writing a
>> conditional to use the Security framework on recent macOS and openssl on
>> older macOS, what should happen if perchance the port is used on non-macOS?
>> In this case, the answer is that frameworks are a Mac thing, so you would
>> want to use openssl for non-macOS.
>>
>>
>> > I was under the impression that the `platforms darwin` line means that the
>> > entire Portfile is supposed to be valid only for `${os.platform} eq
>> > "darwin"`, no? (In other words, my understanding is that a line such as
>> > `platforms darwin freebsd openbsd` is meant to signify that "this Portfile
>> > is supposed to be valid for the listed platforms".) If that's not the
>> > case, then what is the purpose of `platforms darwin`?
>>
>> The platforms line is not used by MacPorts in any way at this time, other
>> than to display it in the output of "port info". There is a ticket about
>> possibly using it in the future as a way to indicate which OS versions the
>> port is compatible with, but I don't think that got beyond the idea phase.
>>
>>
