`rustup man cargo` fails on Windows

[pravic]

d:>rustup man cargo
thread '

' panicked at 'failed to open man page: Error { repr: Os { code: 2, message: "\u{41d}\u{435} \u{443}\u{434}\u{430}\u{435}\u{442}\u{441}\u{44f} \u{43d}\u{430}\u{439}\u{442}\u{438} \u{443}\u{43a}\u{430}\u{437}\u{430}\u{43d}\u{43d}\u{44b}\u{439} \u{444}\u{430}\u{439}\u{43b}." } }', ../src/libcore\result.rs:785
note: Run with RUST_BACKTRACE=1 for a backtrace.

d:>set RUST_BACKTRACE=1

d:>rustup man cargo
thread '

' panicked at 'failed to open man page: Error { repr: Os { code: 2, message: "\u{41d}\u{435} \u{443}\u{434}\u{430}\u{435}\u{442}\u{441}\u{44f} \u{43d}\u{430}\u{439}\u{442}\u{438} \u{443}\u{43a}\u{430}\u{437}\u{430}\u{43d}\u{43d}\u{44b}\u{439} \u{444}\u{430}\u{439}\u{43b}." } }', ../src/libcore\result.rs:785

d:>

[Boddlnagg]

Yeah, it tries to run the man program, which does not exist on Windows. I think we should just disable rustup man on Windows. Some Windows users might not even know what a man page is.

[brson]

Huh, it definitely shouldn't panic. I expected it to return a reasonable error. There must be an unwrap that should be a chain_err somewhere.