Why is xmake unable to find a library it just built?

[smac89]

This is a snippet of the output from Github Actions:

C:\hostedtoolcache\windows\xmake\2.9.6\x64\winenv\bin\curl -SL -A "Xmake/2.9.6+HEAD.abd15c255 (Windows;) curl/8.2.1" https://github.com/libexpat/libexpat/releases/download/R_2_6_3/expat-2.6.3.tar.bz2 -o expat-2.6.3.tar.bz2
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed

  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0

100  599k  100  599k    0     0  1494k      0 --:--:-- --:--:-- --:--:-- 1494k
checking for 7z ... C:\hostedtoolcache\windows\xmake\2.9.6\x64\winenv\bin\7z
C:\hostedtoolcache\windows\xmake\2.9.6\x64\winenv\bin\7z x -y expat-2.6.3.tar.bz2 -snl- -oC:\Users\RUNNER~1\AppData\Local\Temp\.xmake\241122\_493AC1595E2145708B5528F8EAF5C3B0.tar

7-Zip 19.00 (x64) : Copyright (c) 1999-2018 Igor Pavlov : 2019-02-21

Scanning the drive for archives:
1 file, 613404 bytes (600 KiB)

Extracting archive: expat-2.6.3.tar.bz2
--
Path = expat-2.6.3.tar.bz2
Type = bzip2

Everything is Ok

Size:       3686400
Compressed: 613404
C:\hostedtoolcache\windows\xmake\2.9.6\x64\winenv\bin\7z x -y C:\Users\RUNNER~1\AppData\Local\Temp\.xmake\241122\_493AC1595E2145708B5528F8EAF5C3B0.tar\expat-2.6.3.tar -snl- -osource.tmp

7-Zip 19.00 (x64) : Copyright (c) 1999-2018 Igor Pavlov : 2019-02-21

Scanning the drive for archives:
1 file, 3686400 bytes (3600 KiB)

Extracting archive: C:\Users\RUNNER~1\AppData\Local\Temp\.xmake\241122\_493AC1595E2145708B5528F8EAF5C3B0.tar\expat-2.6.3.tar
--
Path = C:\Users\RUNNER~1\AppData\Local\Temp\.xmake\241122\_493AC1595E2145708B5528F8EAF5C3B0.tar\expat-2.6.3.tar
Type = tar
Physical Size = 3686400
Headers Size = 96768
Code Page = UTF-8

Everything is Ok

Folders: 13
Files: 164
Size:       3546280
Compressed: 3686400
  => download https://github.com/libexpat/libexpat/releases/download/R_2_6_3/expat-2.6.3.tar.bz2 .. ok
checking for gcc ... ok
checking for the c++ compiler (cxx) ... gcc
checking for pkgconf ... no
checking for pkgconf ... no
checking for pkg-config ... ok
checking for cmake ... C:\Program Files\CMake\bin\cmake
checking for ar ... ok
checking for the static library archiver (ar) ... ar
checking for pkgconf ... no
checking for pkgconf ... no
checking for pkg-config ... ok
C:\Program Files\CMake\bin\cmake -DEXPAT_BUILD_EXAMPLES=OFF -DEXPAT_BUILD_TESTS=OFF -DEXPAT_BUILD_DOCS=OFF -DCMAKE_BUILD_TYPE=Release -DEXPAT_SHARED_LIBS=OFF -DEXPAT_CHAR_TYPE=char -DEXPAT_MSVC_STATIC_CRT=ON -DCMAKE_INSTALL_PREFIX=D:\a\game-server\game-server\build\.packages\e\expat\2.6.3\9a62aaa2af7e462e822d3e23f718313b -DCMAKE_INSTALL_LIBDIR:PATH=lib -G Ninja -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded -DCMAKE_COMPILE_PDB_OUTPUT_DIRECTORY=pdb -DCMAKE_POSITION_INDEPENDENT_CODE=ON "-DCMAKE_C_FLAGS_RELEASE= -O3 -DNDEBUG" -DCMAKE_SHARED_LINKER_FLAGS_RELEASE= -DCMAKE_EXE_LINKER_FLAGS_RELEASE= "-DCMAKE_CXX_FLAGS_RELEASE= -O3 -DNDEBUG" -DCMAKE_STATIC_LINKER_FLAGS_RELEASE= C:\Users\runneradmin\AppData\Local\.xmake\cache\packages\2411\e\expat\2.6.3\source
CMake Deprecation Warning at CMakeLists.txt:37 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.


-- The C compiler identification is GNU 14.2.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: D:/a/_temp/w64devkit/bin/gcc.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Looking for dlfcn.h
-- Looking for dlfcn.h - not found
-- Looking for fcntl.h
-- Looking for fcntl.h - found
-- Looking for inttypes.h
-- Looking for inttypes.h - found
-- Looking for memory.h
-- Looking for memory.h - found
-- Looking for stdint.h
-- Looking for stdint.h - found
-- Looking for stdlib.h
-- Looking for stdlib.h - found
-- Looking for strings.h
-- Looking for strings.h - found
-- Looking for string.h
-- Looking for string.h - found
-- Looking for sys/stat.h
-- Looking for sys/stat.h - found
-- Looking for sys/types.h
-- Looking for sys/types.h - found
-- Looking for unistd.h
-- Looking for unistd.h - found
-- Looking for getpagesize
-- Looking for getpagesize - not found
-- Looking for mmap
-- Looking for mmap - not found
-- Looking for getrandom
-- Looking for getrandom - not found
-- Looking for arc4random_buf
-- Looking for arc4random_buf - not found
-- Looking for arc4random
-- Looking for arc4random - not found
-- Looking for 4 include files stdlib.h, ..., float.h
-- Looking for 4 include files stdlib.h, ..., float.h - found
-- Performing Test HAVE_OFF_T
-- Performing Test HAVE_OFF_T - Success
-- Performing Test HAVE_SYSCALL_GETRANDOM
-- Performing Test HAVE_SYSCALL_GETRANDOM - Failed
CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_CXX_FLAGS_RELEASE
    EXPAT_MSVC_STATIC_CRT


-- Performing Test FLAG_NO_STRICT_ALIASING
-- Performing Test FLAG_NO_STRICT_ALIASING - Success
-- Performing Test FLAG_VISIBILITY
-- Performing Test FLAG_VISIBILITY - Success
-- Looking for cos in m
-- Looking for cos in m - found
-- ===========================================================================
-- 
-- Configuration
--   Generator .................. Ninja
--   Build type ................. Release
--   Prefix ..................... D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b
--   Shared libraries ........... OFF
--   Character type ............. char (UTF-8)
--   Library name postfix ....... 
-- 
--   Build documentation ........ OFF
--   Build examples ............. OFF
--   Build fuzzers .............. OFF
--   Build tests ................ OFF
--   Build tools (xmlwf) ........ ON
--   Build pkg-config file ...... ON
--   Install files .............. ON
-- 
--   Features
--     // Advanced options, changes not advised
--     Attributes info .......... OFF
--     Context bytes ............ 1024
--     DTD support .............. ON
--     General entities ......... ON
--     Large size ............... OFF
--     Minimum size ............. OFF
--     Namespace support ........ ON
-- 
--   Entropy sources
--     rand_s ................... ON
-- 
-- ===========================================================================
-- Configuring done (4.1s)
-- Generating done (0.0s)
-- Build files have been written to: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/cache/build_9a62aaa2
checking for pkgconf ... no
checking for pkgconf ... no
checking for pkg-config ... ok
checking for ninja ... ok
ninja install -C D:\a\game-server\game-server\build\.packages\e\expat\2.6.3\cache\build_9a62aaa2 -j 3
ninja: Entering directory `D:\a\game-server\game-server\build\.packages\e\expat\2.6.3\cache\build_9a62aaa2'
[1/10] Building C object CMakeFiles/expat.dir/lib/xmlrole.c.obj
[2/10] Building C object CMakeFiles/xmlwf.dir/xmlwf/codepage.c.obj
[3/10] Building C object CMakeFiles/expat.dir/lib/xmlparse.c.obj
[4/10] Building C object CMakeFiles/xmlwf.dir/xmlwf/readfilemap.c.obj
[5/10] Building C object CMakeFiles/expat.dir/lib/xmltok.c.obj
[6/10] Building C object CMakeFiles/xmlwf.dir/xmlwf/xmlwf.c.obj
[7/10] Linking C static library libexpat.a
[8/10] Building C object CMakeFiles/xmlwf.dir/xmlwf/xmlfile.c.obj
[9/10] Linking C executable xmlwf\xmlwf.exe
[9/10] Install the project...
-- Install configuration: "Release"
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/include/expat_config.h
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/lib/libexpat.a
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/include/expat.h
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/include/expat_external.h
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/lib/pkgconfig/expat.pc
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/bin/xmlwf.exe
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/share/man/man1/xmlwf.1
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/share/doc/expat/AUTHORS
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/share/doc/expat/changelog
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/lib/cmake/expat-2.6.3/expat-config.cmake
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/lib/cmake/expat-2.6.3/expat-config-version.cmake
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/lib/cmake/expat-2.6.3/expat.cmake
-- Installing: D:/a/game-server/game-server/build/.packages/e/expat/2.6.3/9a62aaa2af7e462e822d3e23f718313b/lib/cmake/expat-2.6.3/expat-release.cmake
checking for xmake::expat ... expat 2.6.3
{ 
  defines = "XML_STATIC",
  static = true,
  version = "2.6.3",
  license = "MIT",
  sysincludedirs = { 
    "D:\a\game-server\game-server\build\.packages\e\expat\2.6.3\9a62aaa2af7e462e822d3e23f718313b\include",� 
  },� 
}

error: package(expat): links not found!
  => install expat 2.6.3 .. failed
error: install failed!

As you can see, the library seems to have built and installed correctly, yet xmake is unable to find it...What could be causing this?

[star-hengxing]

It seems that cmake can't find the msvc environment variables then fallback to mingw. My guess is that your configuration is --plat=windows, so xmake can't detect the .lib file and report the error.