Build silently fails on Windows

[leonardus]

>luarocks install lyaml YAML_DIR="C:\PROGRAM FILES\LIBYAML" YAML_INCDIR="C:\PROGRAM FILES\LIBYAML\INCLUDE" YAML_LIBDIR="C:\PROGRAM FILES\LIBYAML"
Installing https://luarocks.org/lyaml-6.2.8-1.src.rock

lyaml 6.2.8-1 depends on lua >= 5.1, < 5.5 (5.4-1 provided by VM)
C:\Program Files\lua/lua.exe build-aux/luke package="lyaml" version="6.2.8" PREFIX="C:\Users\Leonardus\AppData\Roaming/luarocks/lib/luarocks/rocks-5.4/lyaml/6.2.8-1" CFLAGS="/nologo /MD /O2" LIBFLAG="/nologo /dll" LIB_EXTENSION="dll" OBJ_EXTENSION="obj" LUA="C:\Program Files\lua/lua.exe" LUA_DIR="C:\Users\Leonardus\AppData\Roaming/luarocks/lib/luarocks/rocks-5.4/lyaml/6.2.8-1/lua" LUA_INCDIR="C:\Program Files\lua/include" YAML_DIR="C:\PROGRAM FILES\LIBYAML" YAML_INCDIR="C:\PROGRAM FILES\LIBYAML\INCLUDE" YAML_LIBDIR="C:\PROGRAM FILES\LIBYAML"
C:\Program Files\lua/lua.exe build-aux/luke install --quiet INST_LIBDIR="C:\Users\Leonardus\AppData\Roaming/luarocks/lib/luarocks/rocks-5.4/lyaml/6.2.8-1/lib" INST_LUADIR="C:\Users\Leonardus\AppData\Roaming/luarocks/lib/luarocks/rocks-5.4/lyaml/6.2.8-1/lua"
lyaml 6.2.8-1 is now installed in C:\Users\Leonardus\AppData\Roaming/luarocks (license: MIT/X11)

However, lyaml is not installed to %APPDATA%\luarocks\share\lua\5.4, and attempting to load it fails:

>lua script.lua
lua: script.lua:3: module 'lyaml' not found:
        no field package.preload['lyaml']
        no file 'C:\Program Files\luarocks\lua\lyaml.lua'
        no file 'C:\Program Files\luarocks\lua\lyaml\init.lua'
        no file 'C:\Program Files\luarocks\lyaml.lua'
        no file 'C:\Program Files\luarocks\lyaml\init.lua'
        no file 'C:\Program Files\luarocks\..\share\lua\5.4\lyaml.lua'
        no file 'C:\Program Files\luarocks\..\share\lua\5.4\lyaml\init.lua'
        no file '.\lyaml.lua'
        no file '.\lyaml\init.lua'
        no file 'C:\Users\Leonardus\AppData\Roaming/luarocks/share/lua/5.4/lyaml.lua'
        no file 'C:\Users\Leonardus\AppData\Roaming/luarocks/share/lua/5.4/lyaml/init.lua'
        no file ''
        no file 'C:\Program Files\luarocks\lyaml.dll'
        no file 'C:\Program Files\luarocks\..\lib\lua\5.4\lyaml.dll'
        no file 'C:\Program Files\luarocks\loadall.dll'
        no file '.\lyaml.dll'
        no file 'C:\Users\Leonardus\AppData\Roaming/luarocks/lib/lua/5.4/lyaml.dll'
        no file 'C:\Program Files (x86)\wxLua\bin\lyaml.dll'
        no file ''
stack traceback:
        [C]: in function 'require'
        script.lua:3: in main chunk
        [C]: in ?

I attempted to write a rockspec, but there's a linking problem that I've been trying to resolve for about four hours now and I haven't made any progress.

local _MODREV, _SPECREV = 'git', '-1'

package = 'lyaml'
version = _MODREV .. _SPECREV

description = {
   summary  = 'libYAML binding for Lua',
   detailed = 'Read and write YAML format files with Lua.',
   homepage = 'http://github.com/gvvaughan/lyaml',
   license  = 'MIT/X11',
}

source = {
   url = 'http://github.com/gvvaughan/lyaml/archive/v' .. _MODREV .. '.zip',
   dir = 'lyaml-' .. _MODREV,
}

dependencies = {
   'lua >= 5.1, < 5.5',
}

external_dependencies = {
   YAML = {
     header = 'yaml.h',
     --library = 'yaml',
   },
}

build = {
   type = 'builtin',
   modules = {
      yaml = {
         sources = {
            'ext/yaml/emitter.c',
            'ext/yaml/parser.c',
            'ext/yaml/scanner.c',
            'ext/yaml/yaml.c'
         },
         incdirs = { '$(YAML_INCDIR)', '$(LUA_INCDIR)' },
         libdirs = { '$(YAML_LIBDIR)', '$(YAML_BINDIR)' },
         libraries = { 'yaml' },
         defines = {
            'PACKAGE=lyaml',
            'VERSION=' .. _MODREV,
            'NDEBUG=1',
            '_FORTIFY_SOURCE=2'
         }
      }
   },
   install = {
      lua = {
         ['lyaml'] = 'lib/lyaml/init.lua',
         ['lyaml.explicit'] = 'lib/lyaml/explicit.lua',
         ['lyaml.functional'] = 'lib/lyaml/functional.lua',
         ['lyaml.implicit'] = 'lib/lyaml/implicit.lua'
      },
   },
   copy_directories = {'doc'}
}

if _MODREV == 'git' then
   build.copy_directories = nil

   source = {
      url = 'git://github.com/gvvaughan/lyaml.git',
   }
end

Below is the linking error, if anyone is interested and/or more experienced than me with building on Windows:

>luarocks make YAML_DIR="c:\program files\libyaml"

lyaml git-1 depends on lua >= 5.1, < 5.5 (5.4-1 provided by VM)
cl /nologo /MD /O2 -c -Foext/yaml/emitter.obj -IC:\Program Files\lua/include ext/yaml/emitter.c -DPACKAGE=lyaml -DVERSION=git -DNDEBUG=1 -D_FORTIFY_SOURCE=2 -Ic:\program files\libyaml/include -IC:\Program Files\lua/include
emitter.c
cl /nologo /MD /O2 -c -Foext/yaml/parser.obj -IC:\Program Files\lua/include ext/yaml/parser.c -DPACKAGE=lyaml -DVERSION=git -DNDEBUG=1 -D_FORTIFY_SOURCE=2 -Ic:\program files\libyaml/include -IC:\Program Files\lua/include
parser.c
cl /nologo /MD /O2 -c -Foext/yaml/scanner.obj -IC:\Program Files\lua/include ext/yaml/scanner.c -DPACKAGE=lyaml -DVERSION=git -DNDEBUG=1 -D_FORTIFY_SOURCE=2 -Ic:\program files\libyaml/include -IC:\Program Files\lua/include
scanner.c
cl /nologo /MD /O2 -c -Foext/yaml/yaml.obj -IC:\Program Files\lua/include ext/yaml/yaml.c -DPACKAGE=lyaml -DVERSION=git -DNDEBUG=1 -D_FORTIFY_SOURCE=2 -Ic:\program files\libyaml/include -IC:\Program Files\lua/include
yaml.c
link -dll -def:yaml.def -out:yaml.dll C:\Program Files\lua/lib/lua5.4.lib ext/yaml/emitter.obj ext/yaml/parser.obj ext/yaml/scanner.obj ext/yaml/yaml.obj -libpath:c:\program files\libyaml -libpath:c:\program files\libyaml/bin yaml.lib
Microsoft (R) Incremental Linker Version 14.38.33133.0
Copyright (C) Microsoft Corporation.  All rights reserved.

lua5.4.lib(lstate.obj) : MSIL .netmodule or module compiled with /GL found; restarting link with /LTCG; add /LTCG to the link command line to improve linker performance
Microsoft (R) Incremental Linker Version 14.38.33133.0
Copyright (C) Microsoft Corporation.  All rights reserved.

   Creating library yaml.lib and object yaml.exp
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_stream_start_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_stream_end_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_document_start_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_document_end_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_alias_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_scalar_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_sequence_start_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_sequence_end_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_mapping_start_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_mapping_end_event_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_emitter_initialize
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_emitter_delete
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_emitter_set_output
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_emitter_set_width
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_emitter_set_unicode
emitter.obj : error LNK2001: unresolved external symbol __imp_yaml_emitter_emit
parser.obj : error LNK2001: unresolved external symbol __imp_yaml_event_delete
parser.obj : error LNK2001: unresolved external symbol __imp_yaml_parser_initialize
scanner.obj : error LNK2001: unresolved external symbol __imp_yaml_parser_initialize
parser.obj : error LNK2001: unresolved external symbol __imp_yaml_parser_delete
scanner.obj : error LNK2001: unresolved external symbol __imp_yaml_parser_delete
parser.obj : error LNK2001: unresolved external symbol __imp_yaml_parser_set_input_string
scanner.obj : error LNK2001: unresolved external symbol __imp_yaml_parser_set_input_string
parser.obj : error LNK2001: unresolved external symbol __imp_yaml_parser_parse
scanner.obj : error LNK2001: unresolved external symbol __imp_yaml_token_delete
scanner.obj : error LNK2001: unresolved external symbol __imp_yaml_parser_scan
yaml.dll : fatal error LNK1120: 23 unresolved externals

Error: Build error: Failed compiling module yaml.dll

I built libyaml as a static library; installing from luarocks also silently fails the same way when libyaml is built as a .dll.

[leonardus]

I've also tried building libyaml as a shared library, which allows to successfully compile, link, and install lyaml with the modified Rockspec, just with this error when trying to load ylaml (specifically when include('yaml') is called).