Lots of errors running swift-driver integration tests

I'm guessing that there has been significant changes, so I'm hoping someone can help point me to how running the apple/swift tests with apple/swift-driver is suppose to work now.

My process is:
Running the following in the swift directory:

utils/build-script --skip-build-benchmarks \
  --skip-ios --skip-watchos --skip-tvos --swift-darwin-supported-archs "$(uname -m)" \
  --sccache --release-debuginfo --swift-disable-dead-stripping --test

The running this to run the tests using swift-driver:

  SWIFT_DRIVER_LIT_DIR=/Users/cschlosser/workspace/swift-source/build/Ninja-RelWithDebInfoAssert/swift-macosx-x86_64/test-macosx-x86_64 \
  swift test -c release -Xswiftc -enable-testing --parallel --filter SwiftDriverTests.IntegrationTests > test-output.log

My xcode-select is pointing at Xcode 12.5 using the default toolchain. I thought maybe I needed a newer toolchain, but I tried several ways of using the latest development toolchain and still didn't have any success.

I'm getting a lot of failures, some of the common ones are:

Swift/ContiguousArrayBuffer.swift:429: Fatal error: Array storage is not immutable
Current stack trace:
0    libswiftCore.dylib                 0x000000010ce64d70 _swift_stdlib_reportFatalErrorInFile + 106
1    libswiftCore.dylib                 0x000000010cad9b90 closure #1 in closure #1 in closure #1 in _assertionFailure(_:_:file:line:flags:) + 387
2    libswiftCore.dylib                 0x000000010cad9970 closure #1 in closure #1 in _assertionFailure(_:_:file:line:flags:) + 321
3    libswiftCore.dylib                 0x000000010cad9730 closure #1 in _assertionFailure(_:_:file:line:flags:) + 131
4    libswiftCore.dylib                 0x000000010cad9240 _assertionFailure(_:_:file:line:flags:) + 325
5    libswiftCore.dylib                 0x000000010cad95e0 _fatalErrorMessage(_:_:file:line:flags:) + 44
6    libswiftCore.dylib                 0x000000010caad180 specialized _ArrayBuffer.immutableCount.getter + 341
7    libswiftCore.dylib                 0x000000010cbff5c0 specialized _print<A>(_:separator:terminator:to:) + 125
8    libswiftCore.dylib                 0x000000010cbfde90 print(_:separator:terminator:) + 243
9    a.out                              0x000000010ca7d1b0 main + 1525
10   libdyld.dylib                      0x00007fff205bbf3c start + 1
/Users/cschlosser/workspace/swift-source/swift/test/stdlib/tgmath.swift.gyb:36:8: error: no such module 'StdlibUnittest'
import StdlibUnittest

I discovered this issue. It was using the wrong swift-frontend. Seems like this might have been the case for close to a year, but it didn't cause too many issues in the past. Fix here: Provide swift-frontend path when running integration tests by cltnschlosser · Pull Request #646 · apple/swift-driver · GitHub