boost169, boost171, boost176: should set dist_subdir to boost

[ryandesign (Ryan Carsten Schmidt)]

The newly created several boostXYZ ports download their distfiles into different dist subdirs than the old boost port did. So now we have old boost distfiles in ​https://distfiles.macports.org/boost/ and new distfiles, partly duplicating the old ones, in ​https://distfiles.macports.org/boost169/, ​https://distfiles.macports.org/boost171/, ​https://distfiles.macports.org/boost176/. It would be more straightforward and avoid duplication if all the boost ports set their dist_subdir to boost.

[mascguy (Christopher Nielsen)]

Segregation of the distfiles makes logical sense, given that boost will be retired once all dependents have been migrated off of it. But I'm open to the idea.

Chris/Michael, thoughts?

[cjones051073 (Chris Jones)]

I have no strong feelings either way, but given that eventually (hopefully soonish) the old boost port will be obsoleted (and eventually removed) it actually would not save anything in the long run as by construction the versioned boost ports will never overlap in versions.

[michaelld (Michael Dickens)]

I also have no strong feelings either way. It would take a small amount of work to aggregate all of the Boost distfiles into the same directory, but I don't see a strong benefit to doing so. There will be no duplication of distfiles, as each BoostXYZ port will have a unique version. Why mess with something that's working and sufficient?

[mascguy (Christopher Nielsen)]

Ryan, given that port boost will be retired once all migrations have been completed, can we close this?

[mascguy (Christopher Nielsen)]

Let's close for now. We can always revisit down the road.