How to fix XCode invivisble Headers and Clang compiler issue in MacOS? - c++

Question

GCC- Apple clang version 11.0.3 (clang-1103.0.32.29) is giving me weird results when I try to run any C++/C program. For example, running this code:
#include <string>
#include <iostream>
int main()
{
std::string hello = "Hello world";
std::cout << hello << std::endl;
return 0;
}
I run with gcc or g++
gcc template.cpp -o template
It gives me this error
In file included from template.cpp:1:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/string:439:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/algorithm:624:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/initializer_list:47:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstddef:38:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stddef.h:50:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__nullptr:23:29: error: variable has incomplete type 'struct _LIBCPP_TEMPLATE_VIS'
struct _LIBCPP_TEMPLATE_VIS nullptr_t
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__nullptr:23:8: note: forward declaration of 'std::__1::_LIBCPP_TEMPLATE_VIS'
struct _LIBCPP_TEMPLATE_VIS nullptr_t
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__nullptr:23:38: error: expected ';' after top level declarator
struct _LIBCPP_TEMPLATE_VIS nullptr_t
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__nullptr:46:52: error: unknown type name 'nullptr_t'
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}
^
In file included from template.cpp:2:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/iostream:40:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/istream:163:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/ostream:140:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/locale:192:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdlib:167:44: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY long abs( long __x) _NOEXCEPT {return labs(__x);}
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stdlib.h:110:44: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long abs( long __x) _NOEXCEPT {return labs(__x);}
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdlib:135:9: note: using declaration
using ::abs;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdlib:169:44: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY long long abs(long long __x) _NOEXCEPT {return llabs(__x);}
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stdlib.h:112:44: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long long abs(long long __x) _NOEXCEPT {return llabs(__x);}
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdlib:135:9: note: using declaration
using ::abs;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdlib:172:42: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY ldiv_t div( long __x, long __y) _NOEXCEPT {return ldiv(__x, __y);}
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stdlib.h:115:42: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY ldiv_t div( long __x, long __y) _NOEXCEPT {return ldiv(__x, __y);}
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdlib:143:9: note: using declaration
using ::div;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdlib:174:42: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY lldiv_t div(long long __x, long long __y) _NOEXCEPT {return lldiv(__x, __y);}
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stdlib.h:117:42: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY lldiv_t div(long long __x, long long __y) _NOEXCEPT {return lldiv(__x, __y);}
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cstdlib:143:9: note: using declaration
using ::div;
^
7 errors generated.
I think I caused this when I was trying to copy some library header files to /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
Now I am unable to compile any C++ program on my Mac. I can't understand how to fix this.
I tried installing llvm and adding it's path but nothing helps.
> brew install llvm
==> Installing dependencies for llvm: libffi
==> Installing llvm dependency: libffi
==> Downloading https://homebrew.bintray.com/bottles/libffi-3.3.catalina.bottle.tar.gz
######################################################################## 100.0%
==> Pouring libffi-3.3.catalina.bottle.tar.gz
==> Caveats
libffi is keg-only, which means it was not symlinked into /usr/local,
because macOS already provides this software and installing another version in
parallel can cause all kinds of trouble.
For compilers to find libffi you may need to set:
export LDFLAGS="-L/usr/local/opt/libffi/lib"
export CPPFLAGS="-I/usr/local/opt/libffi/include"
For pkg-config to find libffi you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/libffi/lib/pkgconfig"
==> Summary
🍺 /usr/local/Cellar/libffi/3.3: 16 files, 489.4KB
==> Installing llvm
==> Downloading https://homebrew.bintray.com/bottles/llvm-10.0.0_3.catalina.bottle.tar.gz
==> Downloading from https://akamai.bintray.com/ea/ea9b9f579df49499d9ab0084e10edecc5350298d6c5db399a1dabc8694dab7db?__gda__=exp=1587779777~hmac=fa0024a2581a685070cc1612da34abc29c53c8c352dce2f47c74d841c
######################################################################## 100.0%
==> Pouring llvm-10.0.0_3.catalina.bottle.tar.gz
==> Caveats
To use the bundled libc++ please add the following LDFLAGS:
LDFLAGS="-L/usr/local/opt/llvm/lib -Wl,-rpath,/usr/local/opt/llvm/lib"
llvm is keg-only, which means it was not symlinked into /usr/local,
because macOS already provides this software and installing another version in
parallel can cause all kinds of trouble.
If you need to have llvm first in your PATH run:
echo 'export PATH="/usr/local/opt/llvm/bin:$PATH"' >> ~/.zshrc
For compilers to find llvm you may need to set:
export LDFLAGS="-L/usr/local/opt/llvm/lib"
export CPPFLAGS="-I/usr/local/opt/llvm/include"
==> Summary
🍺 /usr/local/Cellar/llvm/10.0.0_3: 7,055 files, 1GB
> echo 'export PATH="/usr/local/opt/llvm/bin:$PATH"' >> ~/.zshrc
> export LDFLAGS="-L/usr/local/opt/llvm/lib"
> export CPPFLAGS="-I/usr/local/opt/llvm/include"
~
Current versions of installed Clang:
> gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 11.0.3 (clang-1103.0.32.29)
Target: x86_64-apple-darwin19.3.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
> g++ version

Answer 1

Well, I found a solution. Earlier I was using XCode Application and I messed up some library files when I was trying to copy header files to /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1
It turned so fatal that I was totally helpless. Neither my C++ or C code would compile, nor Node Applications would build due to gyp.
Apparently it some more errors, when I tried to reinstall few things and my homebrew gave a page full of errors with unbrewed header files.
Solution:
I removed Xcode Application, switched to Command line tool.
Removed llvm, and it worked.
You need to switch the XCode path, you do it by:
sudo xcode-select --switch /Library/Developer/CommandLineTools
You are good to go, and never mess up with the files inside SDK, else it will cost you hours of panic. Cheers.

Answer 2

I had to re-install the xcode tools for some weird reason...
sudo rm -rf $(xcode-select -print-path)
xcode-select --install

Answer 3

I had similar issues building a meteor app that had a node-gyp dependency, in the end I was able to follow the instructions here to get the build to work
Specifically exporting this flag:
export LDFLAGS=-L/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib
The failure looked like
> bufferutil#4.0.4 install /Users/ben.ritchie/Documents/dev/connect4/connect4mvp/node_modules/bufferutil
> node-gyp-build
CC(target) Release/obj.target/bufferutil/src/bufferutil.o
In file included from ../src/bufferutil.c:2:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/assert.h:42:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/cdefs.h:807:2: error: Unsupported architecture
#error Unsupported architecture
^
In file included from ../src/bufferutil.c:3:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/node_api.h:12:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api.h:24:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api_types.h:8:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.3/include/stdint.h:47:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/stdint.h:52:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:33:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/machine/_types.h:34:2: error: architecture not supported
#error architecture not supported
^
In file included from ../src/bufferutil.c:3:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/node_api.h:12:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api.h:24:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api_types.h:8:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.3/include/stdint.h:47:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/stdint.h:52:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:55:9: error: unknown type name '__int64_t'
typedef __int64_t __darwin_blkcnt_t; /* total blocks */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:56:9: error: unknown type name '__int32_t'
typedef __int32_t __darwin_blksize_t; /* preferred block size */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:57:9: error: unknown type name '__int32_t'
typedef __int32_t __darwin_dev_t; /* dev_t */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:60:9: error: unknown type name '__uint32_t'
typedef __uint32_t __darwin_gid_t; /* [???] process and group IDs */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:61:9: error: unknown type name '__uint32_t'
typedef __uint32_t __darwin_id_t; /* [XSI] pid_t, uid_t, or gid_t*/
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:62:9: error: unknown type name '__uint64_t'; did you mean 'uint64_t'?
typedef __uint64_t __darwin_ino64_t; /* [???] Used for 64 bit inodes */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_types/_uint64_t.h:31:28: note: 'uint64_t' declared here
typedef unsigned long long uint64_t;
^
In file included from ../src/bufferutil.c:3:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/node_api.h:12:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api.h:24:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api_types.h:8:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.3/include/stdint.h:47:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/stdint.h:52:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:68:9: error: unknown type name '__darwin_natural_t'
typedef __darwin_natural_t __darwin_mach_port_name_t; /* Used by mach */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:70:9: error: unknown type name '__uint16_t'
typedef __uint16_t __darwin_mode_t; /* [???] Some file attributes */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:71:9: error: unknown type name '__int64_t'
typedef __int64_t __darwin_off_t; /* [???] Used for file sizes */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:72:9: error: unknown type name '__int32_t'
typedef __int32_t __darwin_pid_t; /* [???] process and group IDs */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:73:9: error: unknown type name '__uint32_t'
typedef __uint32_t __darwin_sigset_t; /* [???] signal set */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:74:9: error: unknown type name '__int32_t'
typedef __int32_t __darwin_suseconds_t; /* [???] microseconds */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:75:9: error: unknown type name '__uint32_t'
typedef __uint32_t __darwin_uid_t; /* [???] user IDs */
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types.h:76:9: error: unknown type name '__uint32_t'
typedef __uint32_t __darwin_useconds_t; /* [???] microseconds */
^
In file included from ../src/bufferutil.c:3:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/node_api.h:12:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api.h:24:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api_types.h:8:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.3/include/stdint.h:47:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/stdint.h:53:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types/_intptr_t.h:30:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/machine/types.h:37:2: error: architecture not supported
#error architecture not supported
^
In file included from ../src/bufferutil.c:3:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/node_api.h:12:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api.h:24:
In file included from /Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/include/node/js_native_api_types.h:8:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.3/include/stdint.h:47:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/stdint.h:53:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types/_intptr_t.h:32:9: error: unknown type name '__darwin_intptr_t'
typedef __darwin_intptr_t intptr_t;
^
18 errors generated.
make: *** [Release/obj.target/bufferutil/src/bufferutil.o] Error 1
gyp ERR! build error
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack at ChildProcess.onExit (/Users/ben.ritchie/.meteor/packages/meteor-tool/.2.5.0.sgqk5k.nggn++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:194:23)
gyp ERR! stack at ChildProcess.emit (events.js:314:20)
gyp ERR! stack at Process.ChildProcess._handle.onexit (internal/child_process.js:276:12)
gyp ERR! System Darwin 19.6.0
gyp ERR! command "/Users/ben.ritchie/.meteor/packages/meteor-tool/.2.0.0.1fm8up2.pjm8++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/bin/node" "/Users/ben.ritchie/.meteor/packages/meteor-tool/.2.5.0.sgqk5k.nggn++os.osx.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.osx.x86_64/dev_bundle/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /Users/ben.ritchie/Documents/dev/connect4/connect4mvp/node_modules/bufferutil
gyp ERR! node -v v12.20.1
gyp ERR! node-gyp -v v5.1.0
gyp ERR! not ok

Answer 4

Just change:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1