pyrox.dev
1#!/usr/bin/env bash
2set -e
3
4# --print: avoid dependency on environment
5optPrint=
6if [ "$1" == "--print" ]; then
7 optPrint=true
8 shift
9fi
10
11if [ "$#" != 1 ] && [ "$#" != 2 ]; then
12 cat <<EOF
13 Usage: $0 [--print] from-commit-spec [to-commit-spec]
14 You need to be in a git-controlled nixpkgs tree.
15 The current state of the tree will be used if the second commit is missing.
16
17 Examples:
18 effect of latest commit:
19 $ $0 HEAD^
20 $ $0 --print HEAD^
21 effect of the whole patch series for 'staging' branch:
22 $ $0 origin/staging staging
23EOF
24 exit 1
25fi
26
27# A slightly hacky way to get the config.
28parallel="$(echo 'config.rebuild-amount.parallel or false' | nix-repl . 2>/dev/null \
29 | grep -v '^\(nix-repl.*\)\?$' | tail -n 1 || true)"
30
31echo "Estimating rebuild amount by counting changed Hydra jobs (parallel=${parallel:-unset})."
32
33toRemove=()
34
35cleanup() {
36 rm -rf "${toRemove[@]}"
37}
38trap cleanup EXIT
39
40MKTEMP='mktemp --tmpdir nix-rebuild-amount-XXXXXXXX'
41
42nixexpr() {
43 cat <<EONIX
44 let
45 lib = import $1/lib;
46 hydraJobs = import $1/pkgs/top-level/release.nix
47 # Compromise: accuracy vs. resources needed for evaluation.
48 { supportedSystems = cfg.systems or [ "x86_64-linux" "x86_64-darwin" ]; };
49 cfg = (import $1 {}).config.rebuild-amount or {};
50
51 recurseIntoAttrs = attrs: attrs // { recurseForDerivations = true; };
52
53 # hydraJobs leaves recurseForDerivations as empty attrmaps;
54 # that would break nix-env and we also need to recurse everywhere.
55 tweak = lib.mapAttrs
56 (name: val:
57 if name == "recurseForDerivations" then true
58 else if lib.isAttrs val && val.type or null != "derivation"
59 then recurseIntoAttrs (tweak val)
60 else val
61 );
62
63 # Some of these contain explicit references to platform(s) we want to avoid;
64 # some even (transitively) depend on ~/.nixpkgs/config.nix (!)
65 blacklist = [
66 "tarball" "metrics" "manual"
67 "darwin-tested" "unstable" "stdenvBootstrapTools"
68 "moduleSystem" "lib-tests" # these just confuse the output
69 ];
70
71 in
72 tweak (builtins.removeAttrs hydraJobs blacklist)
73EONIX
74}
75
76# Output packages in tree $2 that weren't in $1.
77# Changing the output hash or name is taken as a change.
78# Extra nix-env parameters can be in $3
79newPkgs() {
80 # We use files instead of pipes, as running multiple nix-env processes
81 # could eat too much memory for a standard 4GiB machine.
82 local -a list
83 for i in 1 2; do
84 local l
85 l="$($MKTEMP)"
86 list[$i]="$l"
87 toRemove+=("$l")
88
89 local expr
90 expr="$($MKTEMP)"
91 toRemove+=("$expr")
92 nixexpr "${!i}" > "$expr"
93
94 nix-env -f "$expr" -qaP --no-name --out-path --show-trace $3 \
95 | sort > "${list[$i]}" &
96
97 if [ "$parallel" != "true" ]; then
98 wait
99 fi
100 done
101
102 wait
103 comm -13 "${list[@]}"
104}
105
106# Prepare nixpkgs trees.
107declare -a tree
108for i in 1 2; do
109 if [ -n "${!i}" ]; then # use the given commit
110 dir="$($MKTEMP -d)"
111 tree[$i]="$dir"
112 toRemove+=("$dir")
113
114 git clone --shared --no-checkout --quiet . "${tree[$i]}"
115 (cd "${tree[$i]}" && git checkout --quiet "${!i}")
116 else #use the current tree
117 tree[$i]="$(pwd)"
118 fi
119done
120
121newlist="$($MKTEMP)"
122toRemove+=("$newlist")
123# Notes:
124# - the evaluation is done on x86_64-linux, like on Hydra.
125# - using $newlist file so that newPkgs() isn't in a sub-shell (because of toRemove)
126newPkgs "${tree[1]}" "${tree[2]}" '--argstr system "x86_64-linux"' > "$newlist"
127
128# Hacky: keep only the last word of each attribute path and sort.
129sed -n 's/\([^. ]*\.\)*\([^. ]*\) .*$/\2/p' < "$newlist" \
130 | sort | uniq -c
131
132if [ -n "$optPrint" ]; then
133 echo
134 cat "$newlist"
135fi