After even further investigation, Does guix processes output the desired rec format? It seems hard to select the child process pid:
ChildProcess: 16923: guile --no-auto-compile -L /gnu/store/8a0wry8cvr405ha8d8bpjyzj5dzghigd-module-import /gnu/store/mh1fkn1d9c9mg6hihxvjngxmn3qjmp38-ungoogled-chromium-86.0.4240.111-0.c34a56d-guile-builder ChildProcess: 31859: /gnu/store/ah16zr8mmfkqy23rr7jy5a842ca1q9h1-guile-3.0.4/bin/guile \ /gnu/store/xi3jc6476vyv2vmcsfa1xkpqbxp1apk6-guix-1.1.0-27.1c21468/bin/.guix-real substitute --query ChildProcess: 31869: /gnu/store/ah16zr8mmfkqy23rr7jy5a842ca1q9h1-guile-3.0.4/bin/guile \ /gnu/store/xi3jc6476vyv2vmcsfa1xkpqbxp1apk6-guix-1.1.0-27.1c21468/bin/.guix-real offload x86_64-linux 0 1 0 After perusing info recutils some, I expected the output to be more like: ChildProcessPID: 16923 ChildProcessCommand: guile --no-auto-compile -L /gnu/store/8a0wry8cvr405ha8d8bpjyzj5dzghigd-module-import /gnu/store/mh1fkn1d9c9mg6hihxvjngxmn3qjmp38-ungoogled-chromium-86.0.4240.111-0.c34a56d-guile-builder ChildProcessPID: 31859 ChildProcessCommand: /gnu/store/ah16zr8mmfkqy23rr7jy5a842ca1q9h1-guile-3.0.4/bin/guile \ /gnu/store/xi3jc6476vyv2vmcsfa1xkpqbxp1apk6-guix-1.1.0-27.1c21468/bin/.guix-real substitute --query ChildProcessPID: 31869 ChildProcessCommand: /gnu/store/ah16zr8mmfkqy23rr7jy5a842ca1q9h1-guile-3.0.4/bin/guile \ /gnu/store/xi3jc6476vyv2vmcsfa1xkpqbxp1apk6-guix-1.1.0-27.1c21468/bin/.guix-real offload x86_64-linux 0 1 0 But even that does not capture that the child processes all belong to the session. I must be missing something about the rec format or querying. Any clues? Thanks, John