.envrc

   1 # manual config
   2 nix_version=2.3
   3 nix_openpgp=B541D55301270E0BCF15CA5D8170B4726D7198DE
   4 nixpkgs_channel=nixos-unstable-small
   5 nixshell_sources=(.envrc shell.nix $(test ! -d shell || find shell -type f -not -name "*~" | sort))
   6
   7 # nix
   8 if ! has nix || test "$(nix --version)" != "nix (Nix) $nix_version"
   9 then log_status "installing Nix core tools"
  10   if test ! -e .config/nix/install -o ! -e .config/nix/install.asc
  11   then
  12     mkdir -p .config/nix
  13     (cd .config/nix; curl -OO https://nixos.org/releases/nix/nix-"$nix_version"/{install,install.asc})
  14     gpg2 --keyserver hkp://keys.gnupg.net --recv-keys "$nix_openpgp"
  15   fi
  16   test -e ~/.nix-profile/etc/profile.d/nix.sh || {
  17     gpg --verify .config/nix/install.asc &&
  18     sh .config/nix/install
  19   }
  20   . ~/.nix-profile/etc/profile.d/nix.sh
  21 fi
  22
  23 # nixpkgs
  24 if test ! -e .config/nixpkgs-channel/$nixpkgs_channel.nix
  25 then log_status "installing nixpkgs from $nixpkgs_channel (This may take some time. To update: delete .config/nixpkgs-channel/$nixpkgs_channel.nix)"
  26   rev=$(curl -L https://nixos.org/channels/"$nixpkgs_channel"/git-revision | head -n1 | tr -dC 'a-z0-9')
  27   sha256=$(nix-prefetch-url --unpack https://github.com/NixOS/nixpkgs-channels/archive/"$rev".tar.gz)
  28   mkdir -p .config/nixpkgs-channel
  29   echo >.config/nixpkgs-channel/$nixpkgs_channel.nix "builtins.fetchTarball {url=\"https://github.com/NixOS/nixpkgs-channels/archive/$rev.tar.gz\"; sha256=\"$sha256\";}"
  30 else log_status "using nixpkgs from .config/nixpkgs-channel/$nixpkgs_channel.nix"
  31 fi
  32 watch_file .config/nixpkgs-channel/$nixpkgs_channel.nix
  33 # Used in shell.nix
  34 export nixpkgs_channel
  35 # Get the store path of this nixpkgs,
  36 # it will not be registered as a root for the garbage-collector
  37 # but will be preserved as long as it is used by shell.nix
  38 # which itself will produce a registered derivation.
  39 #nixpkgs=$(nix-instantiate --eval .config/nixpkgs-channel/$nixpkgs_channel.nix)
  40 #nixpkgs=${nixpkgs#'"'}
  41 #nixpkgs=${nixpkgs%'"'}
  42 #export NIX_PATH="nixpkgs=$nixpkgs${NIX_PATH:+:$NIX_PATH}"
  43
  44 # nix-shell
  45 has shasum || { log_error "shasum is needed to cache environment"; return 1; }
  46 for e in "${nixshell_sources[@]}"
  47 do watch_file "$e"; done
  48 hash=$(shasum -a 256 "${nixshell_sources[@]}" | shasum -a 256 | cut -c -64)
  49 if test -e ".cache/nix-shell/$hash/dump"
  50 then
  51   log_status "reusing .cache/nix-shell/$hash/"
  52   # Load the cached environment
  53   direnv_load cat .cache/nix-shell/"$hash"/dump
  54   # Re-run the shellHook to update envvars like GPG_TTY,
  55   # and run gpg-connect-agent updatestartuptty /bye
  56   eval "$shellHook"
  57 else log_status "building .cache/nix-shell/$hash/"
  58   mkdir -p ".cache/nix-shell/$hash"
  59   local dump="$(mktemp .cache/nix-shell/$hash/dump-XXXXXXXX)"
  60   # Register the derivation as a root for the garbage-collector,
  61   # then cache a dump of the environment from within the nix-shell,
  62   # then unregister previous derivations,
  63   # then load the cached environment.
  64   nix-instantiate >/dev/null ./shell.nix \
  65    --indirect --add-root .cache/nix-shell/"$hash"/shell.drv \
  66    ${TRACE:+--show-trace} \
  67    ${OFFLINE:+--option substituters ""} &&
  68   nix-store >/dev/null \
  69    --indirect --add-root .cache/nix-shell/"$hash"/shell.dep \
  70    ${OFFLINE:+--option substituters ""} \
  71    --realise $(nix-store --query --references .cache/nix-shell/"$hash"/shell.drv) &&
  72   nix-shell >"$dump" ${TRACE:+--show-trace} --pure \
  73   --run "$(join_args "$direnv" dump)" \
  74    ${OFFLINE:+--option substituters ""} &&
  75   mv -f "$dump" .cache/nix-shell/"$hash"/dump &&
  76   find .cache/nix-shell -mindepth 1 -maxdepth 1 -not -name "$hash" -exec rm -rf {} + &&
  77   direnv_load cat .cache/nix-shell/"$hash"/dump || {
  78     rm -rf "$PWD/.cache/nix-shell/$hash"
  79     log_error "cannot build shell.nix"
  80     return 1
  81   }
  82 fi