Passing strings in the MANPAGER variable doesn't work, for example:

$ export MANPAGER="sh -c 'col -bx | bat -l man -p'"
$ man 2 select

-bx: 1: -bx: Syntax error: Unterminated quoted string

This happens regardless of the shell I'm using, and even if I change the sh to bash, dash, or fish. For some reason, man doesn't understand strings and spaces in the MANPAGER variable.