Re: Help adding a graph backend

[Julien Lepiller <julien@lepiller.eu>]

As the message says, use ./configure --localstatedir=/var :)

Le 10 février 2023 04:10:02 GMT+01:00, Kyle Andrews <kyle@posteo.net> a écrit :
>
>Dear Guix,
>
>I am not very comfortable editing Guix source code. However, I would
>very much like to add a new backend for `guix graph`. Right now guix
>graph descriptions can only be exported into special purpose tools like
>graphviz, D3, and cypher. I would like to add a fourth option which
>would support loading the dependency data into general purpose network analysis software tools: an edgelist backend.
>
>=> https://en.wikipedia.org/wiki/Edge_list
>
>I think this code will do the job, but I don't know how to test it. So, I don't know for sure.
>
>``` guix/graph.scm
>(define (el-prologue name port)
>  (display "from, to" port))
>
>(define (el-epilogue port)
>  (display "\n" port))
>
>(define (el-node id label port)
>  (display "" port))
>
>(define (el-edge id1 id2 port)
>  (format port "~a, ~a\n"))
>
>(define %edgelist-backend
>  (graph-backend "edgelist"
>                 "Generate graph in CSV edge list format"
>                 el-prologue el-epilogue
>                 el-node el-edge))
>
>(define %graph-backends
>  (list %graphviz-backend
>        %d3js-backend
>        %cypher-backend
>        %edgelist-backend)) ; <- the new proposed backend
>```
>
>Maybe it would be using some incantation involving ./pre-inst-env? I gave it a try following the manual:
>
>```
>cd ~/{{path/to/guix}}
>guix shell -D guix
>./bootstrap
>./configure
>```
>
>This gave an error:
>
>```
>configure: error: chosen localstatedir '/usr/local/var' does not match that of the existing installation '/var'
>Installing may corrupt /gnu/store!
>Use './configure --localstatedir=/var'.
>```
>
>Since I am not that excited about corrupting my /gnu/store given that I don't know what I am doing, I didn't proceed further. 
>
>I figured because I wanted to extend Guix with a new feature and that I
>could piece together a story in my head about how the code should look, my query should be sent to this list rather than to help-guix.
>
>Thanks in advance for any helpful suggestions towards getting this backend added to Guix!
>
>Cheers,
>Kyle
>