nixos/hydra: use set-default in hydra-env wrapper package #287257

Evaluator Performance Report

stat	before	after	Δ	Δ%
cpuTime	538.60	545.94	↗ 7.34	1.36%
envs-bytes	19,475,209,176	19,475,209,176	0
envs-elements	1,022,326,669	1,022,326,669	0
envs-number	706,037,239	706,037,239	0
gc-heapSize	54,949,552,128	55,134,101,504	↗ 184,549,376	0.34%
gc-totalBytes	115,091,074,896	115,091,065,056	↘ 9,840	-0.00%
list-bytes	2,915,384,672	2,915,384,672	0
list-concats	60,859,520	60,859,520	0
list-elements	364,423,084	364,423,084	0
nrAvoided	860,267,397	860,267,397	0
nrFunctionCalls	656,240,582	656,240,582	0
nrLookups	342,000,883	342,000,883	0
nrOpUpdateValuesCopied	1,673,145,576	1,673,145,576	0
nrOpUpdates	78,063,573	78,063,573	0
nrPrimOpCalls	323,941,433	323,941,433	0
nrThunks	936,610,677	936,610,677	0
sets-bytes	37,067,182,400	37,067,182,400	0
sets-elements	2,182,724,985	2,182,724,985	0
sets-number	133,973,915	133,973,915	0
sizes-Attr	16	16	0
sizes-Bindings	16	16	0
sizes-Env	16	16	0
sizes-Value	24	24	0
symbols-bytes	2,275,693	2,275,693	0
symbols-number	164,464	164,464	0
values-bytes	29,325,500,376	29,325,500,376	0
values-number	1,221,895,849	1,221,895,849	0