Things I should be working on: graduate school personal statements.
What I actually spent the last five hours working on: transparent xmobar.
It uses the horrible “grab Pixmap from root X window” hack. You can grab the patch here but I haven’t put in enough effort to actually make this a configurable option; if you just compile that branch, you’ll get an xmobar that is at 100/255 transparency, tinted black. (The algorithm needs a bit of work to generalize over different tints properly; suggestions solicted!) Maybe someone else will cook up a more polished patch. (Someone should also drum up a more complete set of XRender bindings!)
Read more...
I upgraded from Ubuntu Natty Narwhal to Oneiric Ocelot (11.10) today. Lots of things broke. In order:
- “Could not calculate the upgrade.” No indication of what the error might be; in my case, the error ended up being old orphan OpenAFS kernel modules (for whom no kernel modules existed). I also took the opportunity to clean up my PPAs.
- “Reading changelogs.”
apt-listchanges isn’t particularly useful, and I don’t know why I installed it. But it’s really painful when it’s taking more time to read changelogs than to install your software. Geoffrey suggested gdb -p `pgrep apt-listchanges and then forcing it to call exit(0)`, which worked like a charm. Had to do this several times; thought it was infinitely looping. - Icons didn’t work, menus ugly. Go to “System Settings > Appearance” and go set a new theme; in all likelihood your old theme went away. This AskUbuntu question gave a clue.
- Network Manager stopped working. For some inscrutable reason the default NetworkManager config file
/etc/NetworkManager/NetworkManager.conf has managed=false for ifupdown. Flip back to true. - New window manager, new defaults to dunk you in Unity at least once. Just make sure you pick the right window manager from the little gear icon.
gnome-power-manager went away. If you fix icons a not-so-useful icon will show up anyway when you load gnome-settings-daemon.- “Waiting for network configuration.” There were lots of suggestions here. My
/var/run and /var/lock were borked so I did these instructions, I also hear that you should punt wlan0 from /etc/network/interfaces and remove it from /etc/udev/rules.d70-persistent-net.rules. I also commented out the sleeps in /init/failsafe.conf for good measure. - Default GHC is 7.0.3! Blow away your
.cabal (but hold onto .cabal/config) and go reinstall Haskell Platform. Don’t forget to make sure you install profiling libraries, and grab xmonad and xmonad-contrib. Note that previous haskell-platform installs will be rather broken, on account of missing GHC 6 binaries (you can reinstall them, but it looks like they get replaced.) - ACPI stopped knowing about X, so if you have scripts for handling rotation, source
/usr/share/acpi-support/power-funcs and run getXuser and getXconsole - DBUS didn’t start. This is due to leftover pid and socket files, see this bug
- Was mysteriously fscking my root drive on every boot. Check your
pass param in /etc/fstab; should be 0. - Redshift mysteriously was being reset by xrandr calls; worked around by calling it oneshot immediately after running xrandr.
- Not sure if this was related to the upgrade, but fixed an annoyance where suspend-checking (in case you are coming out of hibernate) was taking a really long time in boot. Set
resume to right swap in /etc/initramfs-tools/conf.d/resume and update-initramfs -u with great prejudice).
Unresolved annoyances: X11 autolaunching in DBUS, the power icon doesn’t always properly show AC information and is too small in stalonetray, xmobar doesn’t support percentage battery and AC coloring simultaneously (I have a patch), a totem built from scratch segfaults.
Read more...
tl;dr — Save this page for future reference.
Have you ever been in the situation where you need to quickly understand what a piece of code in some unfamiliar language does? If the language looks a lot like what you’re comfortable with, you can usually guess what large amounts of the code does; even if you may not be completely familiar how all the language features work.
For Haskell, this is a little more difficult, since Haskell syntax looks very different from traditional languages. But there’s no really deep difference here; you just have to squint at it just right. Here is a fast, mostly incorrect, and hopefully useful guide for interpreting Haskell code like a Pythonista. By the end, you should be able to interpret this fragment of Haskell (some code elided with ...):
Read more...