Mysterious "must have a value" error

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The command you want requires the GAP package HAPprime, no longer being developed: its repository at GitHub is archived, and some of the code has been migrated to HAP.

That said, you can still install it by downloading the package's compressed tarball and unpacking it in your ~/.gap/pkg/ folder (after creating it if necessary).

To do that on CoCalc, open a CoCalc terminal and run the following commands (skip the initial $ on each line which represents the prompt):

$ GAP_PKG='~/.gap/pkg'
$ mkdir -p $GAP_PKG
$ cd $GAP_PKG
$ URL=https://files.gap-system.org/gap48/tar.gz/packages
$ TGZ=happrime-0.6.tar.gz
$ wget $URL/$TGZ
$ tar xf $TGZ

Then you can use the desired GAP command, either directly in GAP or in Sage (via gap or, better, libgap) after loading the package HAPprime.

In Sage:

sage: libgap.LoadPackage("happrime")
#I  HAP warning: Set BROWSER_PATH manually if needed.
true
sage: G = libgap.SmallGroup(64, 134)
sage: R = libgap.ResolutionPrimePowerGroupRadical(G, 10)
sage: R
Resolution of length 10 in characteristic 2 for <pc group of size 64 with 6 generators> .
No contracting homotopy available.
A partial contracting homotopy is available.