cabal v2-install could not resolve dependencies

[agitter]

I followed the readme cabal-install instructions

cabal v2-update
cabal v2-install --install-method=copy pandoc pandoc-crossref pandoc-citeproc

on the GitHub-hosted runner ubuntu-20.04. I received the following error

cabal-install version 3.6.2.0
compiled using version 3.6.2.0 of the Cabal library 
Config file path source is default config file.
Config file /home/runner/.cabal/config not found.
Writing default configuration to /home/runner/.cabal/config
Downloading the latest package list from hackage.haskell.org
Updated package list of hackage.haskell.org to the index-state 2022-03-18T21:12:32Z
Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] trying: pandoc-crossref-0.3.12.2 (user goal)
[__1] trying: roman-numerals-0.5.1.5 (dependency of pandoc-crossref)
[__2] next goal: bytestring (dependency of roman-numerals)
[__2] rejecting: bytestring-0.11.1.0/installed-0.11.1.0 (conflict:
roman-numerals => bytestring>=0.9.1 && <0.11)
[__2] skipping: bytestring-0.11.3.0, bytestring-0.11.2.0, bytestring-0.11.1.0,
bytestring-0.11.0.0 (has the same characteristics that caused the previous
version to fail: excluded by constraint '>=0.9.1 && <0.11' from
'roman-numerals')
[__2] trying: bytestring-0.10.12.1
[__3] next goal: base (dependency of pandoc-crossref)
[__3] rejecting: base-4.16.0.0/installed-4.16.0.0 (conflict: bytestring =>
base>=4.2 && <4.16)
[__3] skipping: base-4.16.0.0 (has the same characteristics that caused the
previous version to fail: excluded by constraint '>=4.2 && <4.16' from
'bytestring')
[__3] rejecting: base-4.15.1.0, base-4.15.0.0, base-4.[14](https://github.com/agitter/my-manuscript/runs/5606831223?check_suite_focus=true#step:6:14).3.0, base-4.14.2.0,
base-4.14.1.0, base-4.14.0.0, base-4.13.0.0, base-4.12.0.0, base-4.11.1.0,
base-4.11.0.0, base-4.10.1.0, base-4.10.0.0, base-4.9.1.0, base-4.9.0.0,
base-4.8.2.0, base-4.8.1.0, base-4.8.0.0, base-4.7.0.2, base-4.7.0.1,
base-4.7.0.0, base-4.6.0.1, base-4.6.0.0, base-4.5.1.0, base-4.5.0.0,
base-4.4.1.0, base-4.4.0.0, base-4.3.1.0, base-4.3.0.0, base-4.2.0.2,
base-4.2.0.1, base-4.2.0.0, base-4.1.0.0, base-4.0.0.0, base-3.0.3.2,
base-3.0.3.1 (constraint from non-upgradeable package requires installed
instance)
[__3] fail (backjumping, conflict set: base, bytestring, pandoc-crossref)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: base, bytestring, pandoc-crossref,
roman-numerals

I'm able to install through brew or conda instead, so this isn't urgent.

[arrowd]

I'm updating GHC in FreeBSD Ports to 9.2.2 and see this build failure too. Can we get a new release supporting 9.2.2, please?

[lierdakil]

1) Don't install cabal-citeproc if you're targeting new-ish pandoc (the corresponding change to documentation was merged today) 2) I see the main issue is with roman-numerals. master dropped this dependency (it's not maintained, so easier to vendor it). Now, I'm not sure if that's all that's necessary, but it should at least try to build. I'll make a release later today (hopefully).

[arrowd]

Thanks, it worked for me!

[agitter]

Thanks for the advice and updated instructions in the readme.