I am trying to emerge specific version of pecl-imagick, and so I tried to run: emerge =pecl-imagick-3.1.0_r1 With this result: !!! '=pecl-imagick-3.1.0_r1' is not a valid package atom. !!! Please check ebuild(5) for full details. It seems that having "-" in package name makes portage not recognize the version I want correcly. Tested in portage 2.2_alpha100 and I guess this is valid for every package that has "-" in its name. Expected result: Emerge processing this concrete version of pecl-imagick
You passed the wrong version, it should be # emerge =pecl-imagick-3.1.0_rc1 instead of 3.1.0_r1