Before commit 54fa0cfe4eef7e54e23380704af70ee7b65473ce, the `redshift`
service was run with the environment variable `DISPLAY` set to `:0`.
Commit 54fa0cfe4eef7e54e23380704af70ee7b65473ce changed this to
instead use the value of the `services.xserver.display` configuration
option in the value of the `DISPLAY` variable. In so doing, no default
value was provided for the case where `services.xserver.display` is
`null`.
While the default value of `services.xserver.display` is `0`, use of
which by the `redshift` module would result in `DISPLAY` again being
set to `:0`, `services.xserver.display` may also be `null`, to which
value it is set by, e.g., the `lightdm` module.
In the case that `services.xserver.display` is `null`, with the change
made in commit 54fa0cfe4eef7e54e23380704af70ee7b65473ce, the `DISPLAY`
variable in the environment of the `redshift` service would be set to
`:` (a single colon), which, according to my personal experience,
would result in —
- the `redshift` service failing to start; and
- systemd repeatedly attempting to restart the `redshift` service,
looping indefinitely, while the hapless `redshift` spews error
messages into the journal.
It can be observed that the malformed value of `DISPLAY` is likely at
fault for this issue by executing the following commands in an
ordinary shell, with a suitable `redshift` executable, and the X11
display not already tinted:
- `redshift -O 2500` — This command should reduce the color
temperature of the display (making it more reddish).
- `DISPLAY=':' redshift -O 6500` — This command should raise the
color temperature back up, were it not for the `DISPLAY`
environment variable being set to `:` for it, which should cause
it to, instead, fail with several error messages.
This commit attempts to fix this issue by having the `DISPLAY`
environment variable for the `redshift` service default to its old
value of `:0` in the case that `services.xserver.display` is `null`.
I have tested this solution on NixOS, albeit without the benefit of a
system with multiple displays.
gdnc is a user process and can't be made into a NixOS module very
easily. It can still be put in the user's login script. According to the
GNUstep documentation it will be started as soon as it is needed.
Was meant to go into staging, sorry
This reverts commit 57b2d1e9b0dcdd1d25bd2d450174764b9417ffc1, reversing
changes made to 760b2b9048ea775c319cb348d74447a20dea513e.
- Agent now takes a full URL to the Go.CD server
- Instruct the agent to attempt restart every 30s upon failure
- Test's Accept header did not match the server's expectation
- Replace the tests' complex Awk matches with calls to `jq`
Update gocd-agent package version to 16.6.0-3590 including new sha. Modify heapSize
and maxMemory mkOption to accurately reflect their intended purpose of configuring
initial java heap sizes.
