I get Storeman
You go to OpenRepos’ download page
and then you download the latest attachment and press install.
But what is the best course of action to download and install chum?
I’ve tried downloading and install the Chum GUI installer via storeman,
but the app doesn’t show up in my ‘apps menu’*.
* Not sure if it’s called apps menu, so correct me if I’m wrong.
How to install the SailfishOS:Chum GUI application.
There are instructions on how to deal with install problems on the Chum GUI Installer Openrepos page.
Thanks. Looks like the app is having a fatal error when trying to load.
Download the RPM from https://repo.sailfishos.org/obs/sailfishos:/chum/4.6_aarch64/aarch64/sailfishos-chum-gui-0.6.9-1.10.1.jolla.aarch64.rpm, install, open Settings inside Chum app and set Sailfish version to 4.6.0.15.
The link is for C2 phone?
Yes and no. Technically it’s for architecture of C2 not specifically for C2. That’s why you need to set version manually. But after that it works great.
I tried install Chum but it needs libmapnik.so.3.1 and it’s not installable.
devel-su pkcon install-local harbour-osmscout-s
erver-3.1.0-1.8.1.jolla.aarch64.rpm
Password:
Installing files
Testing changes
Finished
Fatal error: nothing provides ‘libmapnik.so.3.1()(64bit)’ needed by the to be installed harbour-osmscout-server-3.1.0-1.8.1.jolla.aarch64
[defaultuser@JollaC2 Downloads]$ devel-su pkcon install install libmapnik3.1
Password:
Resolving [ ] (0%) Package not found: install
Package not found: libmapnik3.1
Package not found: install
Package not found: libmapnik3.1
Command failed: This tool could not find any available package.
[defaultuser@JollaC2 Downloads]$ devel-su pkcon install libmapnik3.1
Password:
Resolving [ ] (0%) Package not found: libmapnik3.1
Package not found: libmapnik3.1
Command failed: This tool could not find any available package.
To the GPS functions and how to install the Osm scout server, I’ve opened this thread for C2: How to make the GPS work with a Jolla C2? - #9 by danield
Your second command is wrong. Try pkcon install mapnik instead.
Since 3-4 days I get the message "Update the chum repo failed!"on my C2 (5.5.0.61) if I try to update with test version 5.0.0.55 also with previous versions. Does anybody know if the chum repos is down or not available?
Chum repos are not yet available for 5.0. You should use 4.6 for now.
Test version 4.6.0.15 or other 4.6x versions also do not work. 
I get these errors sometimes, when I come home and my phone connects to WLAN. If you haven’t already tried changing the network, I encourage you to do so.
By the way, have you enabled CHUM testing repo in the settings?
Chum:testing dont work on 4.6.0.15…xperia 10V
When I had switched off the test repo completely, a connection could be established. Now it also warks again with version 4.6.0.11. 
When manually specifying a version, for 4
6 and later, use a two-digit version (e.g. 4
6, 5.0), not the full version (5.0.0.55).
… for SailfishOS ≥ 4.6 (only!).
P.S. / Edit:
Yes, now you do not have to (and should not) configure anything specifically any longer when using SailfishOS 4.6 or 5.0.
But this issue (i.e. “no specific Chum repository for this SailfishOS release yet available”) will be recurring with every new, major SailfishOS release (i.e. next: 5.1), as well documented at many places (RTFM).
Ultimately I just wanted to clearly state: Do input a version number with four fields (separated by full stop characters) for SailfishOS < 4.6. and a two fields one for ≥ 4.6, when you have to manually set the SailfishOS version number in the SailfishOS:Chum GUI app.
is there an anticipated date for chum compatibility on SFOS 5.x?
What do you mean? Many of us use it for a long time.
Perhaps a silly question, but how should I interpret the above?