Build instructions

You can use set SDKROOT= to avoid SDK collision, but you also have to take care of the installation path in case of unexpectedly breaking the current installation.

Thank you, now the build did progressed a bit further. By setting SDKROOT=S:\b\1 the build went on. However, it later fails because it cannot find Foundation.

[3/4] Linking Swift executable bin\swift-help.exe
   Creating library bin\swift-help.lib and object bin\swift-help.exp
[3/4] Install the project...-- Install configuration: "Release"
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/SwiftOptions.lib
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin/SwiftOptions.dll
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/SwiftDriver.lib
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin/SwiftDriver.dll
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/lib/SwiftDriverExecution.lib
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin/SwiftDriverExecution.dll
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin/swift-build-sdk-interfaces.exe
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin/swift-driver.exe
-- Installing: S:/Library/Developer/Toolchains/unknown-Asserts-development.xctoolchain/usr/bin/swift-help.exe

The system cannot find the path specified.
The system cannot find the path specified.
-- The ASM compiler identification is MSVC
-- Found assembler: C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.34.31933/bin/Hostx64/x64/cl.exe
-- The C compiler identification is MSVC 19.34.31933.0
-- The Swift compiler identification is Apple 5.8
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.34.31933/bin/Hostx64/x64/cl.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working Swift compiler: S:/b/1/bin/swiftc.exe
-- Check for working Swift compiler: S:/b/1/bin/swiftc.exe - works
-- Configuring done
-- Generating done
-- Build files have been written to: S:/b/8
[308/309] Linking Swift shared library bin\CryptoBoringWrapper.dll
FAILED: bin/CryptoBoringWrapper.dll Sources/CryptoBoringWrapper/CMakeFiles/CryptoBoringWrapper.dir/AEAD/BoringSSLAEAD.swift.obj Sources/CryptoBoringWrapper/CMakeFiles/CryptoBoringWrapper.dir/CryptoKitErrors_boring.swift.obj swift/CryptoBoringWrapper.swiftmodule lib/CryptoBoringWrapper.lib
cmd.exe /C "cd . && S:\b\1\bin\swiftc.exe -output-file-map Sources\CryptoBoringWrapper\CMakeFiles\CryptoBoringWrapper.dir\Release\output-file-map.json -incremental -j 8 -emit-library -o bin\CryptoBoringWrapper.dll -module-name CryptoBoringWrapper -module-link-name CryptoBoringWrapper -emit-module -emit-module-path swift\CryptoBoringWrapper.swiftmodule -emit-dependencies -DCryptoBoringWrapper_EXPORTS -O -libc MD -I S:\SourceCache\swift-crypto\Sources\CCryptoBoringSSL\include -I S:\SourceCache\swift-crypto\Sources\CCryptoBoringSSLShims\include -I S:\b\8\swift S:\SourceCache\swift-crypto\Sources\CryptoBoringWrapper\AEAD\BoringSSLAEAD.swift S:\SourceCache\swift-crypto\Sources\CryptoBoringWrapper\CryptoKitErrors_boring.swift    -Xlinker -implib:lib\CryptoBoringWrapper.lib -L S:\b\8\lib  -L S:\b\8\lib  -L S:\b\8\lib lib\CCryptoBoringSSL.lib  lib\CCryptoBoringSSLShims.lib  lib\CCryptoBoringSSL.lib && cd ."
S:\SourceCache\swift-crypto\Sources\CryptoBoringWrapper\AEAD\BoringSSLAEAD.swift:17:8: error: no such module 'Foundation'
import Foundation
       ^

I think this has to do with that Foundation is built in S:\b\103 rather than S:\b\1.

I bet you misunderstood something… The command set SDKROOT= along is used to unset %SDKROOT% from the environment, so any installed SDK will be transparent for the build system. There’s no need to set this variable when building Swift. Any required module, including Foundation, will be handled by CMake directly.

Yes, I misunderstood. I did a full rebuild with the SDKROOT variable cleared but I got the same error as before.