I'm trying to compile my project, which worked fine before upgrading to Xcode 16, and I'm getting error clang: error: unsupported option '-mno-thumb' for target 'arm64-apple-ios18.0-simulator'. It appears to a similar issue as this BoringSSL-GRPC issue. The fix from StackOverflow was to automatically strip the flag in the Podfile using CocoaPods, but I'm not using CocoaPods. I've grepped the entire project, and I can't find that flag anywhere in the project. Likewise, the full error message doesn't even include -mno-thumb. Does anyone know how I can determine where this flag is being added, so I can remove it?
I've tried this in both Xcode 16.1 and Xcode 16.2 on MacOS Sonoma and Sequoia 15.2.
The full error log is
CompileC /Users/ck/Library/Developer/Xcode/DerivedData/Delta-dwedcmxtirqnkdghmvobshblwrib/Build/Intermediates.noindex/Pods.build/Debug-iphonesimulator/DSDeltaCore.build/Objects-normal/arm64/DSEmulatorBridge.o /Users/ck/Projects/system/Delta/Cores/DSDeltaCore/DSDeltaCore/Bridge/DSEmulatorBridge.mm normal arm64 objective-c++ com.apple.compilers.llvm.clang.1_0.compiler (in target 'DSDeltaCore' from project 'Pods')
cd /Users/ck/Projects/system/Delta/Pods
Using response file: /Users/ck/Library/Developer/Xcode/DerivedData/Delta-dwedcmxtirqnkdghmvobshblwrib/Build/Intermediates.noindex/Pods.build/Debug-iphonesimulator/DSDeltaCore.build/Objects-normal/arm64/af3fcb34312c57c0f52879cdce924b91-common-args.resp
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -x objective-c++ -ivfsstatcache /Users/ck/Library/Developer/Xcode/DerivedData/SDKStatCaches.noindex/iphonesimulator18.2-22C146-07b28473f605e47e75261259d3ef3b5a.sdkstatcache -fmessage-length\=0 -fdiagnostics-show-note-include-stack -fmacro-backtrace-limit\=0 -fno-color-diagnostics -fmodules-prune-interval\=86400 -fmodules-prune-after\=345600 -fbuild-session-file\=/Users/ck/Library/Developer/Xcode/DerivedData/ModuleCache.noindex/Session.modulevalidation -fmodules-validate-once-per-build-session -Wnon-modular-include-in-framework-module -Werror\=non-modular-include-in-framework-module -Wno-trigraphs -Wno-missing-field-initializers -Wno-missing-prototypes -Werror\=return-type -Wdocumentation -Wunreachable-code -Wno-implicit-atomic-properties -Werror\=deprecated-objc-isa-usage -Wno-objc-interface-ivars -Werror\=objc-root-class -Wno-arc-repeated-use-of-weak -Wimplicit-retain-self -Wno-non-virtual-dtor -Wno-overloaded-virtual -Wno-exit-time-destructors -Wduplicate-method-match -Wno-missing-braces -Wparentheses -Wswitch -Wunused-function -Wno-unused-label -Wno-unused-parameter -Wunused-variable -Wunused-value -Wempty-body -Wuninitialized -Wconditional-uninitialized -Wno-unknown-pragmas -Wno-shadow -Wno-four-char-constants -Wno-conversion -Wconstant-conversion -Wint-conversion -Wbool-conversion -Wenum-conversion -Wno-float-conversion -Wnon-literal-null-conversion -Wobjc-literal-conversion -Wshorten-64-to-32 -Wno-newline-eof -Wno-selector -Wno-strict-selector-match -Wundeclared-selector -Wdeprecated-implementations -Wno-c++11-extensions -Wno-implicit-fallthrough -fstrict-aliasing -Wprotocol -Wdeprecated-declarations -Winvalid-offsetof -Wno-sign-conversion -Winfinite-recursion -Wmove -Wcomma -Wblock-capture-autoreleasing -Wstrict-prototypes -Wrange-loop-analysis -Wno-semicolon-before-method-body -Wunguarded-availability -index-store-path /Users/ck/Library/Developer/Xcode/DerivedData/Delta-dwedcmxtirqnkdghmvobshblwrib/Index.noindex/DataStore @/Users/ck/Library/Developer/Xcode/DerivedData/Delta-dwedcmxtirqnkdghmvobshblwrib/Build/Intermediates.noindex/Pods.build/Debug-iphonesimulator/DSDeltaCore.build/Objects-normal/arm64/af3fcb34312c57c0f52879cdce924b91-common-args.resp -w -Xanalyzer -analyzer-disable-all-checks -include /Users/ck/Projects/system/Delta/Pods/Target\ Support\ Files/DSDeltaCore/DSDeltaCore-prefix.pch -MMD -MT dependencies -MF /Users/ck/Library/Developer/Xcode/DerivedData/Delta-dwedcmxtirqnkdghmvobshblwrib/Build/Intermediates.noindex/Pods.build/Debug-iphonesimulator/DSDeltaCore.build/Objects-normal/arm64/DSEmulatorBridge.d --serialize-diagnostics /Users/ck/Library/Developer/Xcode/DerivedData/Delta-dwedcmxtirqnkdghmvobshblwrib/Build/Intermediates.noindex/Pods.build/Debug-iphonesimulator/DSDeltaCore.build/Objects-normal/arm64/DSEmulatorBridge.dia -c /Users/ck/Projects/system/Delta/Cores/DSDeltaCore/DSDeltaCore/Bridge/DSEmulatorBridge.mm -o /Users/ck/Library/Developer/Xcode/DerivedData/Delta-dwedcmxtirqnkdghmvobshblwrib/Build/Intermediates.noindex/Pods.build/Debug-iphonesimulator/DSDeltaCore.build/Objects-normal/arm64/DSEmulatorBridge.o -index-unit-output-path /Pods.build/Debug-iphonesimulator/DSDeltaCore.build/Objects-normal/arm64/DSEmulatorBridge.o
clang: error: unsupported option '-mno-thumb' for target 'arm64-apple-ios18.0-simulator'