These are the steps I used to reproduce it:
Clone the mingw-w64 git repository from Sourceforge: `git clone
https://git.code.sf.net/p/mingw-w64/mingw-w64 mingw-w64-mingw-w64`
Install all the '*mingw*' packages in the Debian Stretch archive:
`sudo apt-get install *mingw*`
For what it's worth, I just tried the latest version of mingw-w64 and I am
not seeing any issue with the CRT getting compiled again when `make
install` is run.
My build scripts are here:
https://github.com/DavidEGrayson/nixcrpkgs/tree/master/mingw-w64
The basic procedure is:
1) Before any mingw-
No, but I did do something similar. I first installed the headers, like you
suggested, but then I created a seperate build directory (build) in the
root tree. I then proceeded to compile the crt, tools, and libraries. While
in the build directory, `make install` still ran the compilation for
mingw-
