ninja -C out/nw ffmpeg
ninja: Entering directory `out/nw'
[1/1] LINK(DLL) ffmpeg.dll ffmpeg.dll.lib ffmpeg.dll.pdb
FAILED: ffmpeg.dll ffmpeg.dll.lib ffmpeg.dll.pdb
ninja -t msvc -e environment.x64 -- ../../third_party/llvm-build/Release+Asserts/bin/lld-link.exe /nologo /IMPLIB:./ffmpeg.dll.lib /DLL /OUT:./ffmpeg.dll /PDB:./ffmpeg.dll.pdb @./ffmpeg.dll.rsp
lld-link: error: undefined symbol: BCryptOpenAlgorithmProvider
>>> referenced by .\..\..\third_party\ffmpeg\libavutil\random_seed.c:126
>>>               obj/third_party/ffmpeg/ffmpeg_internal/random_seed.obj:(av_get_random_seed)

lld-link: error: undefined symbol: BCryptGenRandom
>>> referenced by .\..\..\third_party\ffmpeg\libavutil\random_seed.c:129
>>>               obj/third_party/ffmpeg/ffmpeg_internal/random_seed.obj:(av_get_random_seed)

lld-link: error: undefined symbol: BCryptCloseAlgorithmProvider
>>> referenced by .\..\..\third_party\ffmpeg\libavutil\random_seed.c:130
>>>               obj/third_party/ffmpeg/ffmpeg_internal/random_seed.obj:(av_get_random_seed)

lld-link: error: undefined symbol: ff_vorbis_inverse_coupling_sse
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\vorbisdsp_init.c:41
>>>               obj/third_party/ffmpeg/ffmpeg_internal/autorename_libavcodec_x86_vorbisdsp_init.obj:(ff_vorbisdsp_init_x86)

lld-link: error: undefined symbol: ff_dct32_float_sse2
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\dct_init.c:38
>>>               obj/third_party/ffmpeg/ffmpeg_internal/dct_init.obj:(ff_dct_init_x86)

lld-link: error: undefined symbol: ff_dct32_float_avx
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\dct_init.c:40
>>>               obj/third_party/ffmpeg/ffmpeg_internal/dct_init.obj:(ff_dct_init_x86)

lld-link: error: undefined symbol: ff_imdct_half_sse
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\fft_init.c:49
>>>               obj/third_party/ffmpeg/ffmpeg_internal/fft_init.obj:(ff_fft_init_x86)

lld-link: error: undefined symbol: ff_imdct_calc_sse
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\fft_init.c:49
>>>               obj/third_party/ffmpeg/ffmpeg_internal/fft_init.obj:(ff_fft_init_x86)

lld-link: error: undefined symbol: ff_fft_calc_sse
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\fft_init.c:51
>>>               obj/third_party/ffmpeg/ffmpeg_internal/fft_init.obj:(ff_fft_init_x86)

lld-link: error: undefined symbol: ff_fft_permute_sse
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\fft_init.c:51
>>>               obj/third_party/ffmpeg/ffmpeg_internal/fft_init.obj:(ff_fft_init_x86)

lld-link: error: undefined symbol: ff_imdct_half_avx
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\fft_init.c:57
>>>               obj/third_party/ffmpeg/ffmpeg_internal/fft_init.obj:(ff_fft_init_x86)

lld-link: error: undefined symbol: ff_fft_calc_avx
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\fft_init.c:58
>>>               obj/third_party/ffmpeg/ffmpeg_internal/fft_init.obj:(ff_fft_init_x86)

lld-link: error: undefined symbol: ff_flac_decorrelate_rs_16_sse2
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\flacdsp_init.c:70
>>>               obj/third_party/ffmpeg/ffmpeg_internal/flacdsp_init.obj:(ff_flacdsp_init_x86)

lld-link: error: undefined symbol: ff_flac_decorrelate_ls_16_sse2
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\flacdsp_init.c:70
>>>               obj/third_party/ffmpeg/ffmpeg_internal/flacdsp_init.obj:(ff_flacdsp_init_x86)

lld-link: error: undefined symbol: ff_flac_decorrelate_ms_16_sse2
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\flacdsp_init.c:72
>>>               obj/third_party/ffmpeg/ffmpeg_internal/flacdsp_init.obj:(ff_flacdsp_init_x86)

lld-link: error: undefined symbol: ff_flac_decorrelate_rs_32_sse2
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\flacdsp_init.c:82
>>>               obj/third_party/ffmpeg/ffmpeg_internal/flacdsp_init.obj:(ff_flacdsp_init_x86)

lld-link: error: undefined symbol: ff_flac_decorrelate_ls_32_sse2
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\flacdsp_init.c:82
>>>               obj/third_party/ffmpeg/ffmpeg_internal/flacdsp_init.obj:(ff_flacdsp_init_x86)

lld-link: error: undefined symbol: ff_flac_decorrelate_ms_32_sse2
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\flacdsp_init.c:84
>>>               obj/third_party/ffmpeg/ffmpeg_internal/flacdsp_init.obj:(ff_flacdsp_init_x86)

lld-link: error: undefined symbol: ff_flac_lpc_32_sse4
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\flacdsp_init.c:88
>>>               obj/third_party/ffmpeg/ffmpeg_internal/flacdsp_init.obj:(ff_flacdsp_init_x86)

lld-link: error: undefined symbol: ff_flac_decorrelate_indep8_16_avx
>>> referenced by .\..\..\third_party\ffmpeg\libavcodec\x86\flacdsp_init.c:93
>>>               obj/third_party/ffmpeg/ffmpeg_internal/flacdsp_init.obj:(ff_flacdsp_init_x86)

lld-link: error: too many errors emitted, stopping now (use /errorlimit:0 to see all errors)
ninja: build stopped: subcommand failed.