Vcpkg: Build failure using ./bootstrap-vcpkg.sh in Mac OS X Catalina 10.15

[dev-recon]

Describe the bug
Cannot build vcpkg. I have multiple errors telling that there might be multiple declaration of 'char* ctermid(char*)' and this make the compilation process to stop.

Environment

• OS: Mac OS Catalina - 10.15
• Compiler: gcc 9.1 - XCode 11

To Reproduce
Steps to reproduce the behavior:

1. ./bootstrap-vcpkg.sh
2. See error
   ninja: build stopped: subcommand failed.

Expected behavior
I'm expecting a build successfull

Failure logs
mbpro-e-de-mo-1:vcpkg enm$ ./bootstrap-vcpkg.sh
-- The C compiler identification is AppleClang 11.0.0.11000033
-- The CXX compiler identification is GNU 9.1.0
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Checking whether CXX compiler has -isysroot
-- Checking whether CXX compiler has -isysroot - yes
-- Checking whether CXX compiler supports OSX deployment target flag
-- Checking whether CXX compiler supports OSX deployment target flag - yes
-- Check for working CXX compiler: /usr/local/bin/g++-9
-- Check for working CXX compiler: /usr/local/bin/g++-9 -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Looking for pthread_create
-- Looking for pthread_create - found
-- Found Threads: TRUE
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/enm/dev/vcpkg/toolsrc/build.rel
[0/2] Re-checking globbed directories...
[1/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/base/enums.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/base/enums.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/base/enums.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/base/enums.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/base/enums.cpp.o -c ../src/vcpkg/base/enums.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/base/enums.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char* ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/base/enums.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[2/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/base/machinetype.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/base/machinetype.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/base/machinetype.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/base/machinetype.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/base/machinetype.cpp.o -c ../src/vcpkg/base/machinetype.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/base/machinetype.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/base/machinetype.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[3/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/base/cofffilereader.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/base/cofffilereader.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/base/cofffilereader.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/base/cofffilereader.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/base/cofffilereader.cpp.o -c ../src/vcpkg/base/cofffilereader.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/base/cofffilereader.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/base/cofffilereader.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[4/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/base/checks.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/base/checks.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/base/checks.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/base/checks.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/base/checks.cpp.o -c ../src/vcpkg/base/checks.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/base/checks.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/base/checks.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[5/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/base/downloads.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/base/downloads.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/base/downloads.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/base/downloads.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/base/downloads.cpp.o -c ../src/vcpkg/base/downloads.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/base/downloads.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/base/downloads.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[6/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/base/chrono.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/base/chrono.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/base/chrono.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/base/chrono.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/base/chrono.cpp.o -c ../src/vcpkg/base/chrono.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/base/chrono.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/base/chrono.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[7/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/base/hash.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/base/hash.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/base/hash.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/base/hash.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/base/hash.cpp.o -c ../src/vcpkg/base/hash.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/base/hash.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/base/hash.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[8/66] Building CXX object CMakeFiles/vcpkg.dir/src/vcpkg.cpp.o
FAILED: CMakeFiles/vcpkg.dir/src/vcpkg.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkg.dir/src/vcpkg.cpp.o -MF CMakeFiles/vcpkg.dir/src/vcpkg.cpp.o.d -o CMakeFiles/vcpkg.dir/src/vcpkg.cpp.o -c ../src/vcpkg.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from ../include/vcpkg/base/cstringview.h:4,
from ../include/vcpkg/base/chrono.h:3,
from ../src/vcpkg.cpp:23:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../src/vcpkg.cpp:20:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[9/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/archives.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/archives.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/archives.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/archives.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/archives.cpp.o -c ../src/vcpkg/archives.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/archives.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/archives.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
[10/66] Building CXX object CMakeFiles/vcpkglib.dir/src/vcpkg/base/files.cpp.o
FAILED: CMakeFiles/vcpkglib.dir/src/vcpkg/base/files.cpp.o
/usr/local/bin/g++-9 -DDISABLE_METRICS=0 -I../include -O3 -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -std=c++1z -MD -MT CMakeFiles/vcpkglib.dir/src/vcpkg/base/files.cpp.o -MF CMakeFiles/vcpkglib.dir/src/vcpkg/base/files.cpp.o.d -o CMakeFiles/vcpkglib.dir/src/vcpkg/base/files.cpp.o -c ../src/vcpkg/base/files.cpp
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/wchar.h:90,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/cwchar:44,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/postypes.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/bits/char_traits.h:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/string:40,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/stdexcept:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/array:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/tuple:39,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/functional:54,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/pstl/glue_algorithm_defs.h:13,
from /usr/local/Cellar/gcc/9.1.0/include/c++/9.1.0/algorithm:71,
from ../include/pch.h:22,
from ../src/vcpkg/base/files.cpp:1:
/usr/local/Cellar/gcc/9.1.0/lib/gcc/9/gcc/x86_64-apple-darwin18/9.1.0/include-fixed/stdio.h:222:7: error: conflicting declaration of 'char ctermid(char*)' with 'C' linkage
222 | char *ctermid(char *);
| ^~~
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:525,
from ../include/pch.h:19,
from ../src/vcpkg/base/files.cpp:1:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/_ctermid.h:26:10: note: previous declaration with 'C++' linkage
26 | char *ctermid(char *);
| ^~~
ninja: build stopped: subcommand failed.

Additional context

[cenit]

Build with ./bootstrap-vcpkg.sh --allowAppleClang until the issue with gcc is fixed in homebrew

[dev-recon]

Build with ./bootstrap-vcpkg.sh --allowAppleClang until the issue with gcc is fixed in homebrew

Thanks cenit, worked well.