FFmpeg failed to build due to error C2133: 'ebml_syntax': unknown size with VS2017 on windows

[KarenHuang]

Summary of the bug:
FFmpeg failed to build due to error C2133: 'ebml_syntax': unknown size with VS2017 on windows. This issue can be first reproduced on c1abd95 master revision.Could you please help take a look at this? Thank you!

Steps to reproduce:

1. git clone ​​​​https://github.com/FFmpeg/FFmpeg.git D:\FFmpeg\src
2. Open a VS 2017 x86 prompt and browse to D:\FFmpeg
3. set FFMPEG_TARGET=i386
4. set FFMPEG_SRC_PATH=D:\FFmpeg/src
5. set FFMPEG_FATE_PATH=../fate-suite/
6. set PATH=D:\FFmpeg\tools;%PATH%
7. set MSYS2_PATH_TYPE=inherit
8. .\tools\msys32\usr\bin\sh.exe --login -i -c "/D/ffmpeg/tools/build.sh"

Actual result:
libavformat/matroskadec.c(392): error C2133: 'ebml_syntax': unknown size
libavformat/matroskadec.c(392): error C2133: 'matroska_segment': unknown size
libavformat/matroskadec.c(392): error C2133: 'matroska_track_video_color': unknown size
libavformat/matroskadec.c(392): error C2133: 'matroska_track_video': unknown size
libavformat/matroskadec.c(393): error C2133: 'matroska_track': unknown size
libavformat/matroskadec.c(393): error C2133: 'matroska_track_encoding': unknown size
libavformat/matroskadec.c(393): error C2133: 'matroska_track_encodings': unknown size
libavformat/matroskadec.c(394): error C2133: 'matroska_track_combine_planes': unknown size
libavformat/matroskadec.c(394): error C2133: 'matroska_track_operation': unknown size
libavformat/matroskadec.c(394): error C2133: 'matroska_tracks': unknown size
libavformat/matroskadec.c(395): error C2133: 'matroska_attachments': unknown size
libavformat/matroskadec.c(395): error C2133: 'matroska_chapter_entry': unknown size
libavformat/matroskadec.c(395): error C2133: 'matroska_chapter': unknown size
libavformat/matroskadec.c(395): error C2133: 'matroska_chapters': unknown size
libavformat/matroskadec.c(396): error C2133: 'matroska_index_entry': unknown size
libavformat/matroskadec.c(396): error C2133: 'matroska_index': unknown size
libavformat/matroskadec.c(396): error C2133: 'matroska_tag': unknown size
libavformat/matroskadec.c(396): error C2133: 'matroska_tags': unknown size
libavformat/matroskadec.c(396): error C2133: 'matroska_seekhead': unknown size
libavformat/matroskadec.c(397): error C2133: 'matroska_blockadditions': unknown size
libavformat/matroskadec.c(397): error C2133: 'matroska_blockgroup': unknown size
libavformat/matroskadec.c(397): error C2133: 'matroska_cluster_parsing': unknown size

[KarenHuang]

log_x86_build

[KarenHuang]

Hi ALL,

Could someone looking at this issue?

[Hendrik]

This should be resolved in ab4795a085cd3deacb5e4bbaf527d66171361024