Some powerline enhancements

[ZyX-I]

Added information for qtile and some testing-related code. Note: to make tests actually work powerline/powerline#1316 is required to be merged. I have not actually tested code from this ebuild, except that libvterm builds, tests and installs fine.

[ZyX-I]

Powerline tests appear not to work with sandbox.

[leycec]

It's settled: you're awesome.

Thanks for the tremendous amount of well-documented work you've done here. I've laboriously poured through these commits... and have no significant comments! So, they're in. :facepunch:

[ZyX-I]

This is unfinished: tests still do not work. I have some strange issues with shell tests run in screen: tested shells, be they run in screen or not, simply exit for unknown reason before receiving any input from testing script.

[ZyX-I]

This is after dealing with sandbox.

[ZyX-I]

Without screen shells exit because stdin is closed. Why do they exit with screen?

[ZyX-I]

Disabling sandbox does not help with the problem.

[ZyX-I]

It appears that for some reason bash immediately detaches after it is run: I found a bunch of bash processes that should not be there normally.

So it does not exit, it detaches. Weird.

[ZyX-I]

Actually it is screen who detaches. Failed to create socket?

[ZyX-I]

Yup: AF_UNIX path too long.

[leycec]

Thanks for strenuously debugging this. I've updated the ebuild to explicitly warn users that unit tests currently fail.

I also (...sort of) tracked down the ignorable sandbox warnings "ERROR: ld.so: object 'libsandbox.so' from LD_PRELOAD cannot be preloaded: ignored." The Gentoo Wiki suggests this should only happen under SELinux-enabled profiles, which I am not. To quote:

It happens because SELinux tells glibc to disable LD_PRELOAD (and other environment variables that are considered potentially harmful) during domain transitions.

So, presumably a few Powerline unit tests disable LD_PRELOAD. Which seems a bit odd. In any case, please carry on.

[ZyX-I]

Current problem is not sandbox, it is the fact that

1. screen cannot use path like /var/tmp/portage/app-misc/powerline-9999-r18/work/powerline-9999/tests/shell/home/.screen/powerline-shell-test-bash-25276 for its socket.
2. I cannot use paths outside of /var/tmp/portage/app-misc/powerline-9999-r18 because it what ebuild must do (and trying to do this will most likely result failure with sesandbox (SElinux sandbox, documentation suggests that you must not use this feature by yourself) feature enabled).

Thus I am now trying to switch powerline to use pexpect in place of screen for shell tests. Have a few commits (to this ebuild) to make tests work a bit better.

---

Note: all currently present ebuilds fail to run tests.

[ZyX-I]

Now I have exactly the same problem with socket path length with tmux tests. Problem is that I cannot replace tmux with pexpect because it is tmux integration which is being tested. Guess I need to try to use fakechroot.

[ZyX-I]

Hopefully tmux can use relative paths which are obviously not that big.

[leycec]

screen cannot use path like /var/tmp/portage/app-misc/powerline-9999-r18/work/powerline-9999/tests/shell/home/.screen/powerline-shell-test-bash-25276 for its socket.

That's both surprising and terrible.

Now I have exactly the same problem with socket path length with tmux tests.

Jesus. While I understand the need to cap path lengths (e.g., to avoid buffer overflow attacks), the paths in question aren't that long.

Hopefully tmux can use relative paths which are obviously not that big.

If that fails as well, consider creating a symlink at /var/tmp/portage/app-misc/powerline-9999-r18/work/a pointing to /var/tmp/portage/app-misc/powerline-9999-r18/work/powerline-9999/tests/shell/home/.screen/powerline-shell-test-bash-25276. I haven't actually delved into the tmux codebase, but that should work. The former has a path length of less than 64 bytes, which seems like a reasonable cap. (Stallman save us if the cap is 32 bytes.)

[ZyX-I]

If that fails as well,

It was a statement (i.e. verified). Tmux tests now work, screen were ported to pexpect (according to the documentation the relevant variable (SCREENDIR) should be ignored if screen is suid and screen should be recompiled to change directory instead, so I did not even try to do the same thing with screen: it is sgid (and I thought it is suid because libc removes LD_LIBRARY_PATH from its environment) (sgid screen actually works with SCREENDIR; though I wanted to use pexpect someday in any case because as it allows to wait until output and not for N seconds)).