On Fri, 11 Dec 2020 13:08:55 -0500, Alan Mackenzie wrote: > > Hello, Gentoo. > > I'm angry, because I've wasted several hours trying to decypher a wholly > unintuitive error "message" from emerge. Because of this, it's been too > long since I've been able to update. Help, please! > > The command I typed in was > > # time emerge -auND @world. > > I got back a horrendously long list of packages to merge (most of them > re-merges), followed by: > > emerge: there are no ebuilds built with USE flags to satisfy > "dev-python/pycparser[python_targets_python3_6(-)?,python_targets_python3_7(-)?,python_targets_python3_8(-)?,python_targets_python3_9(-)?,-python_single_target_python3_6(-),-python_single_target_python3_7(-),-python_single_target_python3_8(-),-python_single_target_python3_9(-)]". > !!! One of the following packages is required to complete your request: > - dev-python/pycparser-2.20-r1::gentoo (Change USE: +python_targets_python3_7) > - dev-python/cffi-1.14.0-r3::gentoo (Change USE: -python_targets_python3_7) > (dependency required by "dev-python/cffi-1.14.0-r3::gentoo" [ebuild]) > (dependency required by "dev-python/bcrypt-3.2.0::gentoo" [installed]) > (dependency required by "dev-python/paramiko-2.7.1::gentoo" [installed]) > (dependency required by "dev-vcs/bzr-2.7.0::gentoo" [installed]) > (dependency required by "@selected" [set]) > (dependency required by "@world" [argument]) > > . What is the syntax and semantics of that first line? Is it explained > somewhere in the emerge manual? What do the square brackets mean? What > do the commas within these square brackes mean? AND? OR? What about > the question marks following minus signs inside parentheses? > > What does "(Change USE: +python_targets_python3_7)" mean? Is it a > suggestion to me that I should change some USE flag somewhere? Or is it > telling me that a changed USE flag is the reason for all the trouble? Or > does it mean something else? > > What is "dependency required by" supposed to mean? I can understand a > dependency of A on B. I can understand A being required by B. But a > dependency being required? what does this mean? > > Presumably to get out of the mess I've got to do something with one of > the packages which "is required to complete your request". > > Surely somebody in the Gentoo portage team must see that printing human > readable error messages is a worthwhile thing to do. Surely?
Well, what portage is trying to tell you is that you need to change or add a file in your /etc/portage/package.use directory to specify dev-python/pycparser python_targets_python3_7 and that should fix it -- and if you have --autounmask-use =y (which is the default) it should write the changes for you and after fixing up your package.use file or directlry if necessary, you can proceed. I hope that helps. -- Your life is like a penny. You're going to lose it. The question is: How do you spend it? John Covici wb2una cov...@ccs.covici.com