Realm-cocoa: Xcode 12 Betas 1 and 2 crash when compiling when using Realm 5.2.0 and 5.3.0, is it a known fact?

[friguron]

Goals

Compile successfully with Xcode 12 a project that, as of now, it only compiles ok with Xcode 11.1

Expected Results

Xcode 12 Beta 1 and 2 should not crash using Realm 5.2.0 and 5.3.0 (in the compile phase)

Actual Results

Xcode 12 Beta 1 and 2 both crash using Realm 5.2.0 and 5.3.0 (in the compile phase)

See attachment:

Steps to Reproduce

Using XCode 12 Betas 1 and/or 2, trying to compile our project (using Realm 5.2.0 or 5.3.0) the crash just appears. CMD + R just triggers this.

Code Sample

We can't send confidential code as of now, we should trim and subcase substantial parts of our code. If it's really needed we'll try to do it though.

Version of Realm and Tooling

Realm framework version: 5.2.0 and or 5.3.0
Realm Object Server version: Not used
Xcode version: Xcode 12 Betas 1 and/or 2
iOS/OSX version: Catalina 10.15.4
Dependency manager + version: Cocoapods 1.8.4

[tgoyne]

You currently need to remove x86_64 from the support architectures when building for watchOS as we are not yet publishing a library with a slice for the new 64-bit simulator.

[friguron]

As far as we understand we've removed all "intel" mentions inside this test project we're attaching here:

https://www.dropbox.com/s/ndb0i5fq3yms04v/TestApp_realm_arm_only_with_watch.zip

The compilation error still appears. Should we do anything else to get a successful compilation?

On the other hand, should we expect x86/64 support for watchos targets as we had in previous Realm versions? Is it a known fact you're working on as of now? (for Xcode 12, we mean )
In a worst case we might drop support for Watchos+Realm in the future, but we'd like to know if we should still keep it or not.

Thanks !!

[BrentMifsud]

this is happening in Xcode 11.6 as well.

[tgoyne]

That project is building for "standard architectures". With Xcode 11 that results in building for i386, armv7k, and arm64_32. Xcode 12 has added x86_64 to that list because they added a 64-bit version of the watch simulator. We haven't released a version of the core library for the new simulator yet, so you currently need to explicitly set the supported architectures to the old value of "i386 armv7k arm64_32", or wait a few days for a release with the new architecture to happen.

[BrentMifsud]

That project is building for "standard architectures". With Xcode 11 that results in building for i386, armv7k, and arm64_32. Xcode 12 has added x86_64 to that list because they added a 64-bit version of the watch simulator. We haven't released a version of the core library for the new simulator yet, so you currently need to explicitly set the supported architectures to the old value of "i386 armv7k arm64_32", or wait a few days for a release with the new architecture to happen.

Changing the architecture seems to have broken the cocoapods scripts. I had to add in "i386 armv7k arm64_32 arm64"

[tgoyne]

arm64 should only be needed for the iOS part and not the watchOS part unless something strange is going on.

[BrentMifsud]

arm64 should only be needed for the iOS part and not the watchOS part unless something strange is going on.

we do have a watchOS target as well. It doesn't have realm as a dependency though. Seems to build fine though with the architecture configuration I mentioned above.

Crisis averted for now.

Weird that apple made that architecture change as part of Xcode 11.6 instead of waiting for 12.

[tgoyne]

Xcode 11.6 existing at all is pretty weird. I'm guessing there's some good reason for it, though.

[virtuosovidit]

That project is building for "standard architectures". With Xcode 11 that results in building for i386, armv7k, and arm64_32. Xcode 12 has added x86_64 to that list because they added a 64-bit version of the watch simulator. We haven't released a version of the core library for the new simulator yet, so you currently need to explicitly set the supported architectures to the old value of "i386 armv7k arm64_32", or wait a few days for a release with the new architecture to happen.

What's the expected timeframe for the issue to be fixed? (i.e. Is the workaround the only way to run on simulator for the Beta period this year?)

[tgoyne]

https://github.com/realm/realm-core/pull/3796 is the WIP PR to add the new simulator slice.

[virtuosovidit]

Thanks a lot for sharing that! :)

[saltyskip]

@tgoyne a similar issue with xcode 12.0 beta 2 when compiling a project with extensions. First I receive a warning

linking against a dylib which is not safe for use in application extensions: /Users/drei/Library/Developer/Xcode/DerivedData/IOSTemplateProject-eqmqqnyemwwahcaysepnexgjyyvd/Build/Intermediates.noindex/Previews/IOSTemplateProject/Products/Debug-iphonesimulator/PackageFrameworks/RealmCore.framework/RealmCore

Followed by the exact same build error containing a list of undefined symbols as the OP posted above

[tgoyne]

Well beta 3 has now complicated things by adding arm simulator slices which are distinct from the arm device builds. Adding support for that will be awkward.

[saltyskip]

Note it appears to also appears to affect Swift UI previews as referenced in #6625, which i was also able to reproduce locally

[tgoyne]

SwiftUI previews not working when using spm are unrelated to this one despite having similar symptoms.

[mikeyusc]

Well beta 3 has now complicated things by adding arm simulator slices which are distinct from the arm device builds. Adding support for that will be awkward.

Arm Simulator slices are almost certainly for Apple Silicon Macs.. since the "simulator" there is also running on Arm.