Comment 2 for bug 536869

$ sudo apt-get build-dep gnudatalanguage
Reading package lists... Done
Building dependency tree
Reading state information... Done
Note, selecting libmagick++-dev instead of libmagick++9-dev
Package libplplot-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package libplplot-dev has no installation candidate
E: Failed to satisfy Build-Depends dependency for gnudatalanguage: libplplot-dev
$

How did you build-test this package if libplplot-dev doesn't exist in the archive?