In the file kglobalaccel-5.7.0.ebuild is something wrong in the line "!<kde-plasma/plasma-workspace-5.2.50". If you change it to "!<kde-plasma/plasma-workspace-5.2.0" you can compile it.
You will need to wait for a later plasma release then. The blocker is there for a reason * package kde-frameworks/kglobalaccel-5.7.0 NOT merged * * Detected file collision(s): * * /usr/lib/debug/usr/bin/kglobalaccel5.debug * /usr/bin/kglobalaccel5 * /usr/share/kservices5/kglobalaccel5.desktop * /usr/share/dbus-1/services/org.kde.kglobalaccel.service * * Searching all installed packages for file collisions... * * Press Ctrl-C to Stop * * kde-plasma/plasma-workspace-5.2.0-r1:5::kde * /usr/bin/kglobalaccel5 * /usr/lib/debug/usr/bin/kglobalaccel5.debug * /usr/share/dbus-1/services/org.kde.kglobalaccel.service * /usr/share/kservices5/kglobalaccel5.desktop
I changed my mind, we need to fix this.
Thanks for reporting. This is fixed in kde overlay. You wont be able to compile KF 5.7 until its releaed ;) commits 51b19ed10b4f106cf7092926fab496865ab571ea, 2c0a8b36dd9672967593413523cd00c58b2524e9, 857c7b67cd9f3eddbaefc2e4adce6c8b1a697575