Subport known but not found (was: Re: "concurrent" qt4-mac: request feedback & testing for current port phase in Portfile?)

[René J.V. Bertin]

By "popular request" I'm taking this to the dev ML...

So I'm trying to convert my +libsymlinks convenience variant into a ditto subport, qt4-mac-transitional (better name suggestions still welcome).

I'm stuck at the stage where I simply have

subport ${name}-transitional {
}
if { ${subport} eq "${name}-transitional" } {
    conflicts           qt3 qt3-mac qt5-mac
    if {![info exists qt4_is_concurrent]} {
        return -code error "\n\nERROR:\n\
${name}-transitional is available only when qt4-mac has been installed with +concurrent\n"
    }
}

After redoing portindex, I get:

#> port info qt4-mac
qt4-mac @4.8.6_2 (aqua)
Sub-ports:            qt4-mac-transitional
Variants:             KDE, concurrent, cxx11, debug, demos, examples, htmldocs, noexceptions, odbc, openvg, raster, universal

Description:          Qt Tool Kit: A cross-platform framework (headers, data, and libraries) for writing cross-platform GUI-based
                      applications. Installs to /opt/local
Homepage:             http://qt-project.org

Build Dependencies:   pkgconfig
Library Dependencies: zlib, dbus, openssl, tiff, libpng, libmng, jpeg
Conflicts with:       qt3, qt3-mac, qt5-mac
Platforms:            macosx
License:              LGPL-2.1 GPL-3
Maintainers:          michaelld at macports.org, openmaintainer at macports.org

#> port info qt4-mac-transitional
Error: Port qt4-mac-transitional not found

Erm, IBYP???

(yes, I've been naughty, and introduced variants to build without exceptions -in progress..- and to skip the 200+Mb of HTML docs)