Cygwin terminal in IntelliJ

IntelliJ sports an excellent terminal emulator (the "Terminal" tab at bottom of the editor). By default it brings up a terminal native to your Operating System: CMD.EXE on Windows, $SHELL on Linux and Mac.

However I prefer Cygwin when I work on Windows. WSL is incredible, but there are still interoperability issues between its filesystem and Windows-native programs, and IntelliJ (which relies on java.exe, a Windows-native program) is still working on it.

So, how to open a Cygwin terminal in IntelliJ? Setting the program to start in Settings|Tools|Terminal|Shell path, the most obvious thing to do, does not quite work:

C:\cygwin64\bin\bash.exe

This is a non-interactive shell, and does not source your profile. The next try is:

C:\cygwin64\bin\bash.exe --login -i

This produces an error from IntelliJ that it cannot start the program correctly. A little checking says the leading command needs to be quoted, else IntelliJ treats the entire line as the name of the command, not as a command followed by flags. OK:

"C:\cygwin64\bin\bash.exe" --login -i

Hey, I have a shell! Unfortunately, it starts in my home directory, not in my project root. Starting in the project root is one of the nice features of the terminal in IntelliJ. Finally, two changes. First the IntelliJ setting:

"C:\cygwin64\bin\bash" -c "exec /usr/bin/env INTELLIJ=true $SHELL --login -i"

And an addition to my ~/.bashrc:

${INTELLIJ-false} && cd ${OLDPWD-.}

Ipso presto!