gprbuild install error (2019)

[George J <ivanov_george@list.ru>]

Hi all! Yesterday i tried to install gprbuild from github ( i need a new version to use gnatcoll ). Platform wnd 10 X64. Xmlada components has been installed ideally by instruction (readme.md). To install gprbuild i've installed cygwin first.
(Gprbuild source dir where i'm installing from : C:\GNAT\components\gprbuild)

According to instruction (https://github.com/AdaCore/gprbuild)
1. bootstap - ok
2. make ... setup - ok
3. make all - ok
4. make install - error.
So, that's an error :
"file C:\GNAT\components\gprbuild\exe\production\gprconfig does not exist, build may not be complete"
BUT, if we go to that path, file gprconfig.exe is situated there! And if we manually delete it's extension '.exe' - error will be shown about another file in that directory. So, i've decided to go further. After making copy of that files and deleting all extensions from the names i've got errors about "not finding *.pdf, *doc" and other files in "doc directory". So i left this initiative to fix this problem this way, and i don't know what i do wrong. I've read all issues on that branch on github, but can't find any decision.
Hope someone know, what the problem is.
Thanks!