Investigate dSYM size decrease between v3.3.6 and v3.4.0

[1ec5]

Building the iOS SDK with Xcode 8 would decrease the framework size significantly. Unfortunately, #6842 is keeping us on Xcode 7.3.

Since it’s only the dynamic framework that’s giving Xcode 7.3 users problems, I’m wondering whether we could ship an unstripped dynamic framework and add code in strip-frameworks.sh to strip that framework (in addition to stripping out irrelevant architecture slices as it does now). As it is, you can’t submit to the App Store without having strip-frameworks.sh in a Run Script build phase, so this should cover anyone who needs to use the dynamic framework in a simulator that comes with Xcode 7.3.

Putting on the 3.4.0 milestone for consideration for a beta.

/cc @boundsj

[boundsj]

Here are some notes I took while investigating this a bit more yesterday

• The 3.3.x series branch, when built with Xcode 7.3.1 produces a 50 MB symbol stripped dynamic framework and a 190 MB dSYM
• The 3.3.x series branch when built with Xcode 8.0 produces a 38 MB symbol stripped dynamic framework and a 190 MB dSYM
• The latest 3.4.0 beta, built with Xcode 7.3.1 has a 49 MB symbol stripped dynamic framework and a 34.5 MB dSYM
• The latest 3.4.0 beta, built with Xcode 8.0 has a 37.5 MB symbol stripped dynamic framework and a 36.7 MB dSYM

I think we should use Xcode 8.0+ for future builds. Although we are left with the issue for Xcode 7.3.1 users.

@1ec5 I’m wondering whether we could ship an unstripped dynamic framework and add code in strip-frameworks.sh to strip that framework

I'm not sure if I understand how to pull this off. We currently ship an unstripped (i.e. does not have strip -Sx run on it) mapbox-ios-sdk-#.#.#-symbols-dynamic.zip output that works fine in an Xcode 7.3.1 swift environment. But it would fail if we suggested stripping it in a build phase, I think. But I'm sure I'm missing something.

I'd also like to investigate the large decrease in dSYM size on the 3.4.0 branch. We've gone from ~100 MB to close to 200 MB (in more recent 3.3.x version built with Xcode 7.3.1) to ~37 MB in the 3.4.0 branch using Xcode 8.0

[1ec5]

We shipped v3.3.7 built in Xcode 8; there’s no going back to Xcode 7.3. ⏩ It’s too late in the game to try shipping an unstripped dynamic framework. Do we need to investigate the dSYM size decrease as part of this task for the v3.4.0 release?

[boundsj]

Do we need to investigate the dSYM size decrease as part of this task for the v3.4.0 release?

At this point I'd say no (at least I would not want to block the release on this investigation). A size decrease is a good thing and we seem to be getting nicely symbolicated crash reports from the latest version.

[1ec5]

OK, I pushed this investigation to v3.4.1.

[1ec5]

Closing; we can reopen if we see any issues related to the size decrease.