Windows Build: Cannot open source file: 'tools\lldb\bindings\python\LLDBWrapPython.cpp': No such file or directory


Edition	Windows 10 Pro
Version	20H2
Installed on	‎11/‎18/‎2020
OS build	19042.630
Experience	Windows Feature Experience Pack 120.2212.31.0
Microsoft Visual Studio Enterprise 2019
Version 16.8.2

Repro step and output:

S:\>ninja -C S:\b\1
ninja: Entering directory `S:\b\1'
[2/804] Performing build step for 'libdispatch'
ninja: no work to do.
[3/802] Building CXX object tools\lldb\source\API\CMakeFiles\liblldb.dir\__\__\bindings\python\LLDBWrapPython.cpp.obj
FAILED: tools/lldb/source/API/CMakeFiles/liblldb.dir/__/__/bindings/python/LLDBWrapPython.cpp.obj
C:\PROGRA~2\MICROS~2\2019\ENTERP~1\VC\Tools\MSVC\1428~1.293\bin\Hostx64\x64\cl.exe  /nologo /TP -DEXPORT_LIBLLDB -DGTEST_HAS_RTTI=0 -DLLDB_CONFIGURATION_RELEASE -DLLDB_ENABLE_SWIFT -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_ENABLE_EXTENDED_ALIGNED_STORAGE -D_HAS_EXCEPTIONS=0 -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Itools\lldb\source\API -IS:\llvm-project\lldb\source\API -Itools\lldb\source -IS:\llvm-project\lldb\include -Itools\lldb\include -Iinclude -IS:\llvm-project\llvm\include -I"C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.8_3.8.1776.0_x64__qbz5n2kfra8p0\include" -IS:\llvm-project\llvm\..\clang\include -Itools\lldb\..\clang\include -IS:\swift\include -Itools\lldb\..\swift\include -IS:\llvm-project\lldb\source\. /DWIN32 /D_WINDOWS   /Zc:inline /Zi /Zc:strictStrings /Oi /Zc:rvalueCast /W4 -wd4141 -wd4146 -wd4244 -wd4267 -wd4291 -wd4351 -wd4456 -wd4457 -wd4458 -wd4459 -wd4503 -wd4624 -wd4722 -wd4100 -wd4127 -wd4512 -wd4505 -wd4610 -wd4510 -wd4702 -wd4245 -wd4706 -wd4310 -wd4701 -wd4703 -wd4389 -wd4611 -wd4805 -wd4204 -wd4577 -wd4091 -wd4592 -wd4319 -wd4709 -wd4324 -w14062 -we4238 /Gw /MD /O2 /Ob2   -wd4018 -wd4068 -wd4150 -wd4201 -wd4251 -wd4521 -wd4530  /EHs-c- /GR- -UNDEBUG -std:c++14  /W0 /showIncludes /Fotools\lldb\source\API\CMakeFiles\liblldb.dir\__\__\bindings\python\LLDBWrapPython.cpp.obj /Fdtools\lldb\source\API\CMakeFiles\liblldb.dir\ /FS -c tools\lldb\bindings\python\LLDBWrapPython.cpp
cl : Command line warning D9025 : overriding '/W4' with '/W0'
c1xx: fatal error C1083: Cannot open source file: 'tools\lldb\bindings\python\LLDBWrapPython.cpp': No such file or directory
[28/802] Building CXX object tools\swift\lib\ClangImporter\CMakeFiles\swiftClangImporter.dir\ImportDecl.cpp.obj
ninja: build stopped: subcommand failed.

I'm following the documentation ( to build Swift on Windows. But stuck on this point.

In addition, I believe there should be a mistake in the "Build the toolchain" section:

-D CMAKE_INSTALL_PREFIX=C:\Library\Developer\Toolchains\unknown-Asserts-development.xctoolchain\usr ^

Because C:\Library does not exist.


The CMAKE_INSTALL_PREFIX isn't a mistake, that is the correct path - it will be created during installation.

The error that you are seeing is likely due to an out-of-date checkout of llvm-project; are you sure you are at the current swift/master of the repository?. The file is at llvm-project/LLDBWrapPython.cpp at swift/main · apple/llvm-project (

This location was changed by @JDevlieghere during the last switch, and he might be a better person to diagnose the issue.

1 Like

Thanks for your reply!

I believe it is the swift/main branch:

C:\swift_build>cd llvm-project

C:\swift_build\llvm-project>git branch
* swift/main

After pulling latest changes of llvm-project, this issue is resolved.

Thank you!

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