.envrc

   1 # manual config
   2 nix_version=2.3.3
   3 nix_openpgp=B541D55301270E0BCF15CA5D8170B4726D7198DE
   4 nixpkgs_channel=nixos-unstable-small
   5 nixshell_sources=(.envrc shell.nix overlays.nix
   6  .config/nixpkgs-channel/"$nixpkgs_channel".nix
   7  $(for d in patches shell overlays; do
   8      test ! -d "$d" || find "$d" -type f -not -name "*~"
   9    done | sort
  10  )
  11 )
  12
  13 # nix
  14 if ! has nix || test "$(nix --version)" != "nix (Nix) $nix_version"
  15 then log_status "installing Nix core tools"
  16   gpg2 --keyserver  hkp://p80.pool.sks-keyservers.net:80 --recv-keys "$nix_openpgp"
  17   mkdir -p .config/nix/"$nix_version"
  18   {
  19   flock --exclusive 3
  20   if test ! -s .config/nix/"$nix_version"/install -o ! -s .config/nix/"$nix_version"/install.asc
  21   then
  22     (cd .config/nix/"$nix_version"
  23     curl -LOO https://nixos.org/releases/nix/nix-"$nix_version"/{install,install.asc})
  24   fi
  25   test -e ~/.nix-profile/etc/profile.d/nix.sh || {
  26     gpg --verify .config/nix/"$nix_version"/install.asc &&
  27     sh .config/nix/"$nix_version"/install || {
  28       log_error "cannot install nix-$nix_version"
  29       return 1
  30     }
  31   }
  32   . ~/.nix-profile/etc/profile.d/nix.sh
  33   } 3>>.config/nix/"$nix_version"/install
  34 fi
  35
  36 # nixpkgs
  37 mkdir -p .config/nixpkgs-channel
  38 {
  39 flock --exclusive 3
  40 if test ! -s .config/nixpkgs-channel/$nixpkgs_channel.nix
  41 then log_status "installing nixpkgs from $nixpkgs_channel (This may take some time. To update: delete .config/nixpkgs-channel/$nixpkgs_channel.nix)"
  42   rev=$(curl -L https://nixos.org/channels/"$nixpkgs_channel"/git-revision | head -n1 | tr -dC 'a-z0-9')
  43   sha256=$(nix-prefetch-url --unpack https://github.com/NixOS/nixpkgs-channels/archive/"$rev".tar.gz)
  44   echo >.config/nixpkgs-channel/$nixpkgs_channel.nix \
  45    "builtins.fetchTarball {url=\"https://github.com/NixOS/nixpkgs-channels/archive/$rev.tar.gz\"; sha256=\"$sha256\";}"
  46 else log_status "using nixpkgs from .config/nixpkgs-channel/$nixpkgs_channel.nix"
  47 fi
  48 } 3>>.config/nixpkgs-channel/$nixpkgs_channel.nix
  49 watch_file .config/nixpkgs-channel/$nixpkgs_channel.nix
  50 # Used in shell.nix
  51 export nixpkgs_channel
  52 # Get the store path of this nixpkgs,
  53 # it will not be registered as a root for the garbage-collector
  54 # but will be preserved as long as it is used by shell.nix
  55 # which itself will produce a registered derivation.
  56 #nixpkgs=$(nix-instantiate --eval .config/nixpkgs-channel/$nixpkgs_channel.nix)
  57 #nixpkgs=${nixpkgs#'"'}
  58 #nixpkgs=${nixpkgs%'"'}
  59 #export NIX_PATH="nixpkgs=$nixpkgs${NIX_PATH:+:$NIX_PATH}"
  60
  61 # nix-shell
  62 has shasum || { log_error "shasum is needed to cache environment"; return 1; }
  63 for e in "${nixshell_sources[@]}"
  64 do watch_file "$e"; done
  65 hash=$(shasum -a 256 "${nixshell_sources[@]}" | shasum -a 256 | cut -c -64)
  66 cache=.cache/nix-shell/"$hash"
  67 unset DIRENV_DUMP_FILE_PATH
  68 if test -e "$cache/dump"
  69 then
  70   log_status "reusing $cache/"
  71   {
  72   flock --shared 3
  73   # Load the cached environment
  74   direnv_load sh -c "cat >\$DIRENV_DUMP_FILE_PATH $cache/dump"
  75   # Re-run the shellHook to update envvars like GPG_TTY,
  76   # and run gpg-connect-agent updatestartuptty /bye
  77   eval "$shellHook"
  78   } 3<$cache/dump
  79 else
  80   log_status "building $cache/"
  81   mkdir -p "$cache"
  82   {
  83   flock --exclusive 3
  84   # Register the derivation as a root for the garbage-collector,
  85   # then cache a dump of the environment from within the nix-shell,
  86   # then unregister previous derivations,
  87   # then load the cached environment.
  88   nix-instantiate >/dev/null ./shell.nix --indirect --add-root "$cache"/shell.drv \
  89    ${TRACE:+--show-trace} \
  90    ${OFFLINE:+--option substituters ""} &&
  91   nix-store >/dev/null --indirect --add-root "$cache"/shell.dep \
  92    --realise $(nix-store --query --references $cache/shell.drv) \
  93    ${OFFLINE:+--option substituters ""} &&
  94   direnv_load sh -c "nix-shell ${TRACE:+--show-trace} \
  95    --run \"DIRENV_DUMP_FILE_PATH= $direnv dump | tee $cache/dump >\$DIRENV_DUMP_FILE_PATH\" \
  96    ${OFFLINE:+--option substituters ""}" &&
  97   find .cache/nix-shell -mindepth 1 -maxdepth 1 -not -name "$hash" -exec rm -rf {} + || {
  98     rm -rf "$PWD/.cache/nix-shell/$hash"
  99     log_error "cannot build shell.nix"
 100     return 1
 101   }
 102   } 3>$cache/dump
 103 fi