cygwin in docker workaround

Dockerfile

# escape=`
FROM mcr.microsoft.com/dotnet/framework/sdk:4.8-windowsservercore-ltsc2019

SHELL ["cmd", "/S", "/C"]

# chocolatey package manager
ADD https://chocolatey.org/install.ps1 install.ps1
RUN powershell ./install.ps1

# cygwin and its package manager
# (note that cygwin makes WSL symlinks, which aren't supported 
# by windows docker yet, so we convert them to regular windows symlinks)
ARG CYGWIN_HOME=C:\tools\cygwin
RUN choco install --no-progress -y cygwin cyg-get && `
    cd %CYGWIN_HOME%\dev && `
    del fd && mklink fd "%CYGWIN_HOME%/proc/self/fd" && `
    del stdin && mklink stdin "%CYGWIN_HOME%/proc/self/fd/0" && `
    del stdout && mklink stdout "%CYGWIN_HOME%/proc/self/fd/1" && `
    del stderr && mklink stderr "%CYGWIN_HOME%/proc/self/fd/2" && `
    `
    cd %CYGWIN_HOME%\etc && `
    del hosts && mklink hosts "%WINDIR%\System32\drivers\etc\hosts" && `
    del mtab && mklink mtab "%CYGWIN_HOME%/proc/mounts" && `
    del networks && mklink networks "%WINDIR%\System32\drivers\etc\networks" && `
    del protocols && mklink protocols "%WINDIR%\System32\drivers\etc\protocol" && `
    del services && mklink services "%WINDIR%\System32\drivers\etc\services" && `
    `
    cd %CYGWIN_HOME%\etc\pki\ca-trust\source && `
    del ca-bundle.legacy.crt && mklink ca-bundle.legacy.crt "%CYGWIN_HOME%/usr/share/pki/ca-trust-legacy/ca-bundle.legacy.default.crt" && `
    `
    cd %CYGWIN_HOME%\etc\crypto-policies\back-ends && `
    del bind.config && mklink bind.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/bind.txt" && `
    del gnutls.config && mklink gnutls.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/gnutls.txt" && `
    del java.config && mklink java.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/java.txt" && `
    del krb5.config && mklink krb5.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/krb5.txt" && `
    del libreswan.config && mklink libreswan.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/libreswan.txt" && `
    del nss.config && mklink nss.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/nss.txt" && `
    del openssh.config && mklink openssh.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/openssh.txt" && `
    del opensshserver.config && mklink opensshserver.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/opensshserver.txt" && `
    del openssl.config && mklink openssl.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/openssl.txt" && `
    del opensslcnf.config && mklink opensslcnf.config "%CYGWIN_HOME%/usr/share/crypto-policies/DEFAULT/opensslcnf.txt"

# autoconf
# (note that cygwin makes WSL symlinks, which aren't supported 
# by windows docker yet, so we convert them to regular windows symlinks)
RUN cyg-get automake make && `
    cd %CYGWIN_HOME%\bin && `
    del autoconf && mklink autoconf "%CYGWIN_HOME%/usr/share/autotools/ac-wrapper.sh" && `
    del autoheader && mklink autoheader "%CYGWIN_HOME%/usr/share/autotools/ac-wrapper.sh" && `
    del autom4te && mklink autom4te "%CYGWIN_HOME%/usr/share/autotools/ac-wrapper.sh" && `
    del autoreconf && mklink autoreconf "%CYGWIN_HOME%/usr/share/autotools/ac-wrapper.sh" && `
    del autoscan && mklink autoscan "%CYGWIN_HOME%/usr/share/autotools/ac-wrapper.sh" && `
    del autoupdate && mklink autoupdate "%CYGWIN_HOME%/usr/share/autotools/ac-wrapper.sh" && `
    del ifnames && mklink ifnames "%CYGWIN_HOME%/usr/share/autotools/ac-wrapper.sh" && `
    cd %CYGWIN_HOME%\etc\alternatives && `
    del automake-doc && mklink automake-doc "%CYGWIN_HOME%/usr/share/info/automake1.9.info.gz"