installation fails (after successful build from src)

[m10d]

Describe the bug
I'm experiencing BTRFS quota-related timeshift bugs. I'm trying to install from sources as the latest in the repos for my two machines is old: ubuntu20.04 ==> timeshift20.03 and 22.04 ==> timeshift21.09. After struggling a bit I found #241 which did get me the correct build steps:

sudo apt install meson help2man gettext valac libvte-2.91-dev libgee-0.8-dev libjson-glib-dev libxapp-dev
# Note for others: had tried previously to setup meson via `python3 pip`, but failed several ways including missing `xapp` dependencies that I couldn't figure out

# clone latest
meson setup builddir
meson compile -C builddir/

however, I can't install successfully:

$ sudo meson install -C builddir/
ninja: Entering directory `builddir/'
ninja: no work to do.
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/mesonbuild/mesonmain.py", line 129, in run
    return options.run_func(options)
  File "/usr/lib/python3/dist-packages/mesonbuild/minstall.py", line 514, in run
    installer.do_install(datafilename)
  File "/usr/lib/python3/dist-packages/mesonbuild/minstall.py", line 330, in do_install
    d = pickle.load(ifile)
AttributeError: Can't get attribute 'OctalInt' on <module 'mesonbuild.coredata' from '/usr/lib/python3/dist-packages/mesonbuild/coredata.py'>

To Reproduce
attempt to build & install locally on ubuntu20.04 as above

Expected behavior
installs successfully

NOTE: please fix the install docs! looks like it's already in progress, but perhaps the INSTALL or README.md still need cleanup

System:

• Linux Distribution Name and Version: ubuntu20.04
• Desktop i3
• Application Version commit 8607c9dc8f0121c6a86759a6b626775c5b63b787 (HEAD -> master, tag: master.mint21, tag: master.lmde6, tag: master.lmde5, origin/master, origin/HEAD)