使用cygwin编译的时候遇到ERROR: Failed to create toolchain.

$ ./compile-ffmpeg.sh all
====================
[*] check archs
====================
FF_ALL_ARCHS = armv5 armv7a arm64 x86 x86_64
FF_ACT_ARCHS = armv5 armv7a arm64 x86 x86_64

====================
[*] check env armv5
====================
FF_ARCH=armv5
FF_BUILD_OPT=

--------------------
[*] make NDK standalone toolchain
--------------------
build on CYGWIN_NT-10.0 x86_64
ANDROID_NDK=D:/Work/Tools/Android/android-ndk-r17b
IJK_NDK_REL=17.1.4828580
NDKr17.1.4828580 detected
Cygwin temp prefix=D:/Work/Tools/Cygwin/tmp/
HOST_OS=cygwin
HOST_EXE=.exe
HOST_ARCH=x86_64
HOST_TAG=windows-x86_64
HOST_NUM_CPUS=4
BUILD_NUM_CPUS=8
Auto-config: --arch=arm
ERROR: Failed to create toolchain.

跑compile-ffmpeg.sh all的时候。出现Failed to create toolchain，请教一下是什么情况呢？我看有人用cygwin是编译通过的

Start with compile-ffmpeg.sh and the NDK standalone-toolchain step shown in the log, checking how the Cygwin environment and Android NDK r17b are detected. Reproduce the armv5 run and identify why toolchain creation fails; done means ./compile-ffmpeg.sh all creates the toolchain and proceeds past this step.

Written by the indexing model from the issue text.