# Can't build juceaide - compilers found, and then not found **URL:** \ **Category:** CMake\ **Created:** [June 28, 2021, 8:51pm UTC](https://forum.juce.com/t/cant-build-juceaide-compilers-found-and-then-not-found/46700 "2021-06-28T20:51:22Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![anoesisaudio](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/anoesisaudio/32/1132_2.png) [@anoesisaudio](https://forum.juce.com/u/anoesisaudio)\ **Post date:** [June 28, 2021, 8:51pm UTC](https://forum.juce.com/t/cant-build-juceaide-compilers-found-and-then-not-found/46700/1 "2021-06-28T20:51:22Z")
Hello, I am trying (well, failing, really) to build VS project files using CMake and Ninja with the following command on Windows 10 (using Clang as the compiler and VS2019). ```auto cmake -B_builds -GNinja -DCMAKE_CXX_COMPILER:PATH="C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\Llvm\x64\bin\clang++.exe" -DCMAKE_C_COMPILER:PATH="C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\Llvm\x64\bin\clang.exe" -DCMAKE_RC_COMPILER:PATH="C:\Program Files (x86)\Windows Kits\10\bin\10.0.19041.0\x64\rc.exe" ``` I am getting this output… ```auto -- The C compiler identification is Clang 11.0.0 with GNU-like command-line -- The CXX compiler identification is Clang 11.0.0 with GNU-like command-line -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/Llvm/x64/bin/clang.exe - skipped -- Detecting C compile features -- Detecting C compile features - done -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/Llvm/x64/bin/clang++.exe - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- Found Python: C:/Program Files (x86)/Microsoft Visual Studio/Shared/Python37_64/python.exe (found version "3.7.8") found components: Interpreter -- Looking for pthread.h -- Looking for pthread.h - not found -- Found Threads: TRUE -- Configuring juceaide CMake Error at JUCE/extras/Build/juceaide/CMakeLists.txt:76 (message): Failed to configure juceaide -- The C compiler identification is unknown -- The CXX compiler identification is unknown CMake Error at CMakeLists.txt:30 (project): No CMAKE_C_COMPILER could be found. ``` It seems that CMake is finding the compilers initially, then not finding them when building juceaide. It is quite possible (ok, probable) that I am doing something wildly incorrect, but I’m a bit of a Windows neophyte and my CMake knowledge is incomplete. Can anyone offer any suggestions on how I can get CMake to succeed with these tools? ---
**Author:** ![reuk](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/reuk/32/21494_2.png) [@reuk](https://forum.juce.com/u/reuk)\ **Post date:** [June 28, 2021, 9:10pm UTC](https://forum.juce.com/t/cant-build-juceaide-compilers-found-and-then-not-found/46700/2 "2021-06-28T21:10:24Z")
In our CI, our GNU-Clang and Ninja build sets the following environment variables: ```auto RC = llvm-rc.exe CC = clang.exe CXX = clang++.exe ``` It also adds the `Tools/LLvm/bin` directory to the `PATH` environment variable before the build. Finally, it adds the flag `-fuse-ld=lld-link.exe` to the `CMAKE_CXX_FLAGS`, because otherwise the build would use the MSVC linker, which doesn’t seem to be compatible with LLVM LTO. If you don’t mind giving up Ninja, the Visual Studio exporter is a bit easier to get running with clang. You should be able to just `cmake -G "Visual Studio 16 2019" -T ClangCL -A x64` and get a working clang build. ---
**Author:** ![anoesisaudio](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/anoesisaudio/32/1132_2.png) [@anoesisaudio](https://forum.juce.com/u/anoesisaudio)\ **Post date:** [June 28, 2021, 9:14pm UTC](https://forum.juce.com/t/cant-build-juceaide-compilers-found-and-then-not-found/46700/3 "2021-06-28T21:14:06Z")
Ah, wonderful. I will give that a shot. Thank you! ---
**Author:** ![anoesisaudio](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/anoesisaudio/32/1132_2.png) [@anoesisaudio](https://forum.juce.com/u/anoesisaudio)\ **Post date:** [June 29, 2021, 2:23am UTC](https://forum.juce.com/t/cant-build-juceaide-compilers-found-and-then-not-found/46700/4 "2021-06-29T02:23:46Z")
@reuk **Thank you much.** I got it working (not sure how I did not add those env variables…seems kind of obvious now 🙄). I ended up keeping Ninja which isn’t a requirement now, but will be at some point. Anyway, I did get some warnings so I thought I should let you know. On first glance, they appear to all be related to conversions between data types. See below. (Note: plug-Example and plug-Example\_tests are what is built.) ```auto In file included from ../JUCE/modules/juce_events/juce_events.cpp:83: ../JUCE/modules/juce_events/native/juce_win32_Messaging.cpp:72:61: warning: implicit conversion loses integer precision: 'unsigned long long' to 'DWORD' (aka 'unsigned long') [-Wshorten-64-to-32] data.cbData = ((size_t) localCopy.length() + 1) * sizeof (CharPointer_UTF32::CharType); ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 warning generated. [25/83] Building CXX object plug-Example/plug/CMakeFiles/plug-Example_tests.dir/ __/__ /JUCE/modules/juce_events/juce_events.cpp.obj In file included from ../JUCE/modules/juce_events/juce_events.cpp:83: ../JUCE/modules/juce_events/native/juce_win32_Messaging.cpp:72:61: warning: implicit conversion loses integer precision: 'unsigned long long' to 'DWORD' (aka 'unsigned long') [-Wshorten-64-to-32] data.cbData = ((size_t) localCopy.length() + 1) * sizeof (CharPointer_UTF32::CharType); ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 warning generated. [26/83] Building CXX object plug-Example/plug/CMakeFiles/plug-Example.dir/ __/__ /JUCE/modules/juce_core/juce_core.cpp.obj In file included from ../JUCE/modules/juce_core/juce_core.cpp:219: ../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:46:32: warning: cast from 'std::aligned_storage<44, 4>::type *' (aka '_Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] InitializeCriticalSection ((CRITICAL_SECTION*) &lock); ^ ~~~~~~~~~~~~~~~~~~~~~~~~../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:49:78: warning: cast from 'std::aligned_storage<44, 4>::type *' (aka '_Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] CriticalSection::~CriticalSection() noexcept { DeleteCriticalSection ((CRITICAL_SECTION*) &lock); } ^ ~~~~~~~~~~~~~~~~~~~~~~~~../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:50:77: warning: cast from 'const std::aligned_storage<44, 4>::type *' (aka 'const _Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] void CriticalSection::enter() const noexcept { EnterCriticalSection ((CRITICAL_SECTION*) &lock); } ^ ~~~~~~~~~~~~~~~~~~~~~~~~../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:51:87: warning: cast from 'const std::aligned_storage<44, 4>::type *' (aka 'const _Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] bool CriticalSection::tryEnter() const noexcept { return TryEnterCriticalSection ((CRITICAL_SECTION*) &lock) != FALSE; } ^ ~~~~~~~~~~~~~~~~~~~~~~~~../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:52:77: warning: cast from 'const std::aligned_storage<44, 4>::type *' (aka 'const _Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] void CriticalSection::exit() const noexcept { LeaveCriticalSection ((CRITICAL_SECTION*) &lock); } ^ ~~~~~~~~~~~~~~~~~~~~~~~~ 5 warnings generated. [32/83] Building CXX object plug-Example/plug/CMakeFiles/plug-Example_tests.dir/ __/__ /JUCE/modules/juce_core/juce_core.cpp.obj In file included from ../JUCE/modules/juce_core/juce_core.cpp:219: ../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:46:32: warning: cast from 'std::aligned_storage<44, 4>::type *' (aka '_Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] InitializeCriticalSection ((CRITICAL_SECTION*) &lock); ^ ~~~~~~~~~~~~~~~~~~~~~~~~../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:49:78: warning: cast from 'std::aligned_storage<44, 4>::type *' (aka '_Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] CriticalSection::~CriticalSection() noexcept { DeleteCriticalSection ((CRITICAL_SECTION*) &lock); } ^ ~~~~~~~~~~~~~~~~~~~~~~~~../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:50:77: warning: cast from 'const std::aligned_storage<44, 4>::type *' (aka 'const _Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] void CriticalSection::enter() const noexcept { EnterCriticalSection ((CRITICAL_SECTION*) &lock); } ^ ~~~~~~~~~~~~~~~~~~~~~~~~../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:51:87: warning: cast from 'const std::aligned_storage<44, 4>::type *' (aka 'const _Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] bool CriticalSection::tryEnter() const noexcept { return TryEnterCriticalSection ((CRITICAL_SECTION*) &lock) != FALSE; } ^ ~~~~~~~~~~~~~~~~~~~~~~~~../JUCE/modules/juce_core/native/juce_win32_Threads.cpp:52:77: warning: cast from 'const std::aligned_storage<44, 4>::type *' (aka 'const _Align_type *') to 'CRITICAL_SECTION *' (aka '_RTL_CRITICAL_SECTION *') increases required alignment from 4 to 8 [-Wcast-align] void CriticalSection::exit() const noexcept { LeaveCriticalSection ((CRITICAL_SECTION*) &lock); } ^ ~~~~~~~~~~~~~~~~~~~~~~~~ 5 warnings generated. [78/83] Building CXX object plug-Example/plug/CMakeFiles/plug-Example_tests.dir/ __/__ /JUCE/modules/juce_gui_basics/juce_gui_basics.cpp.obj In file included from ../JUCE/modules/juce_gui_basics/juce_gui_basics.cpp:128: ../JUCE/modules/juce_gui_basics/components/juce_FocusTraverser.cpp:61:52: warning: zero as null pointer constant [-Wzero-as-null-pointer-constant] return getComponentOrderAttributes (a) < getComponentOrderAttributes (b); ^ nullptr C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\include\tuple:759:97: note: while rewriting comparison as call to 'operator<=>' declared here _NODISCARD constexpr common_comparison_category_t<_Synth_three_way_result<_Types1, _Types2>...> operator<=>( ^ ../JUCE/modules/juce_gui_basics/components/juce_FocusTraverser.cpp:141:23: note: in instantiation of function template specialization 'juce::FocusHelpers::findAllComponents' requested here FocusHelpers::findAllComponents (parentComponent, ^ 1 warning generated. ``` ---
**Author:** ![reuk](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/reuk/32/21494_2.png) [@reuk](https://forum.juce.com/u/reuk)\ **Post date:** [June 29, 2021, 7:49am UTC](https://forum.juce.com/t/cant-build-juceaide-compilers-found-and-then-not-found/46700/5 "2021-06-29T07:49:44Z")
Thanks for letting me know. It looks like I might have missed some warnings when building in 64-bit mode rather than 32-bit. I’ll put this on my backlog and update the thread once these are fixed. ---
**Author:** ![reuk](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/reuk/32/21494_2.png) [@reuk](https://forum.juce.com/u/reuk)\ **Post date:** [June 30, 2021, 8:16pm UTC](https://forum.juce.com/t/cant-build-juceaide-compilers-found-and-then-not-found/46700/6 "2021-06-30T20:16:40Z")
Thanks again, those warnings are fixed here: > ---
**Author:** ![anoesisaudio](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/anoesisaudio/32/1132_2.png) [@anoesisaudio](https://forum.juce.com/u/anoesisaudio)\ **Post date:** [July 3, 2021, 3:53pm UTC](https://forum.juce.com/t/cant-build-juceaide-compilers-found-and-then-not-found/46700/7 "2021-07-03T15:53:14Z")
Hi again @reuk Ran into this one today (Windows again). ```auto In file included from ../JUCE/modules/juce_gui_basics/juce_gui_basics.cpp:128: ../JUCE/modules/juce_gui_basics/components/juce_FocusTraverser.cpp:61:52: warning: zero as null pointer constant [-Wzero-as-null-pointer-constant] return getComponentOrderAttributes (a) < getComponentOrderAttributes (b); ^ nullptr C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\include\tuple:759:97: note: while rewriting comparison as call to 'operator<=>' declared here _NODISCARD constexpr common_comparison_category_t<_Synth_three_way_result<_Types1, _Types2>...> operator<=>( ^ ../JUCE/modules/juce_gui_basics/components/juce_FocusTraverser.cpp:141:23: note: in instantiation of function template specialization 'juce::FocusHelpers::findAllComponents' requested here FocusHelpers::findAllComponents (parentComponent, ^ 1 warning generated. ```