Setting known_fail yes should prevent the port from being installed

[ryandesign (Ryan Carsten Schmidt)]

Some ports do this (this is from go):

if {${os.platform} eq "darwin" && ${os.major} < 11} {
    known_fail yes
    pre-fetch {
        ui_error "${name} @${version} requires OS X 10.7 or greater."
        return -code error "incompatible Mac OS X version"
    }
}

In other words in addition to setting known_fail yes it prints an error message in a pre-fetch block to prevent the port from being installed.

It would be great if MacPorts base itself would ensure that the port cannot be installed when known_fail yes is set.

Ports still need an opportunity to specify a reason why they would fail. Maybe a new option could be created for that, so that a portfile could then say:

# hypothetical code
if {${os.platform} eq "darwin" && ${os.major} < 11} {
    known_fail yes
    known_fail_reason requires OS X 10.7 or greater
}

Maybe implementing this would make other smaller enhancements to known_fail yes like #60564 and #60565 unnecessary.

[ctreleaven (Craig Treleaven)]

See also #59640

[jmroot (Joshua Root)]

In d863a7e471d1afb4e405f5c5fbae470e26486a84/macports-base (master):

Check for known_fail before installing

Closes: #60566