.envrc

   1 # manual config
   2 nix_version=2.3.2
   3 nix_openpgp=B541D55301270E0BCF15CA5D8170B4726D7198DE
   4 nixpkgs_channel=nixos-unstable-small
   5 nixshell_sources=(.envrc shell.nix
   6  $(for d in patches shell; do
   7      test ! -d "$d" || find "$d" -type f -not -name "*~"
   8    done | sort
   9  )
  10 )
  11
  12 # nix
  13 if ! has nix || test "$(nix --version)" != "nix (Nix) $nix_version"
  14 then log_status "installing Nix core tools"
  15   gpg2 --keyserver hkp://wwwkeys.de.pgp.net:80 --recv-keys "$nix_openpgp"
  16   {
  17   flock --exclusive 3
  18   if test ! -s .config/nix/install -o ! -s .config/nix/install.asc
  19   then
  20     mkdir -p .config/nix
  21     (cd .config/nix; curl -OO https://nixos.org/releases/nix/nix-"$nix_version"/{install,install.asc})
  22   fi
  23   test -e ~/.nix-profile/etc/profile.d/nix.sh || {
  24     gpg --verify .config/nix/install.asc &&
  25     sh .config/nix/install || {
  26       log_error "cannot install nix-$nix_version"
  27       return 1
  28     }
  29   }
  30   . ~/.nix-profile/etc/profile.d/nix.sh
  31   } 3>>.config/nix/install
  32 fi
  33
  34 # nixpkgs
  35 mkdir -p .config/nixpkgs-channel
  36 {
  37 flock --exclusive 3
  38 if test ! -s .config/nixpkgs-channel/$nixpkgs_channel.nix
  39 then log_status "installing nixpkgs from $nixpkgs_channel (This may take some time. To update: delete .config/nixpkgs-channel/$nixpkgs_channel.nix)"
  40   rev=$(curl -L https://nixos.org/channels/"$nixpkgs_channel"/git-revision | head -n1 | tr -dC 'a-z0-9')
  41   sha256=$(nix-prefetch-url --unpack https://github.com/NixOS/nixpkgs-channels/archive/"$rev".tar.gz)
  42   echo >.config/nixpkgs-channel/$nixpkgs_channel.nix \
  43    "builtins.fetchTarball {url=\"https://github.com/NixOS/nixpkgs-channels/archive/$rev.tar.gz\"; sha256=\"$sha256\";}"
  44 else log_status "using nixpkgs from .config/nixpkgs-channel/$nixpkgs_channel.nix"
  45 fi
  46 } 3>>.config/nixpkgs-channel/$nixpkgs_channel.nix
  47 watch_file .config/nixpkgs-channel/$nixpkgs_channel.nix
  48 # Used in shell.nix
  49 export nixpkgs_channel
  50 # Get the store path of this nixpkgs,
  51 # it will not be registered as a root for the garbage-collector
  52 # but will be preserved as long as it is used by shell.nix
  53 # which itself will produce a registered derivation.
  54 #nixpkgs=$(nix-instantiate --eval .config/nixpkgs-channel/$nixpkgs_channel.nix)
  55 #nixpkgs=${nixpkgs#'"'}
  56 #nixpkgs=${nixpkgs%'"'}
  57 #export NIX_PATH="nixpkgs=$nixpkgs${NIX_PATH:+:$NIX_PATH}"
  58
  59 # nix-shell
  60 has shasum || { log_error "shasum is needed to cache environment"; return 1; }
  61 for e in "${nixshell_sources[@]}"
  62 do watch_file "$e"; done
  63 hash=$(shasum -a 256 "${nixshell_sources[@]}" | shasum -a 256 | cut -c -64)
  64 cache=.cache/nix-shell/"$hash"
  65 unset DIRENV_DUMP_FILE_PATH
  66 if test -e "$cache/dump"
  67 then
  68   log_status "reusing $cache/"
  69   {
  70   flock --shared 3
  71   # Load the cached environment
  72   direnv_load sh -c "cat >\$DIRENV_DUMP_FILE_PATH $cache/dump"
  73   # Re-run the shellHook to update envvars like GPG_TTY,
  74   # and run gpg-connect-agent updatestartuptty /bye
  75   eval "$shellHook"
  76   } 3<$cache/dump
  77 else
  78   log_status "building $cache/"
  79   mkdir -p "$cache"
  80   {
  81   flock --exclusive 3
  82   # Register the derivation as a root for the garbage-collector,
  83   # then cache a dump of the environment from within the nix-shell,
  84   # then unregister previous derivations,
  85   # then load the cached environment.
  86   nix-instantiate >/dev/null ./shell.nix --indirect --add-root "$cache"/shell.drv \
  87    ${TRACE:+--show-trace} \
  88    ${OFFLINE:+--option substituters ""} &&
  89   nix-store >/dev/null --indirect --add-root "$cache"/shell.dep \
  90    --realise $(nix-store --query --references $cache/shell.drv) \
  91    ${OFFLINE:+--option substituters ""} &&
  92   direnv_load sh -c "nix-shell ${TRACE:+--show-trace} \
  93    --run \"DIRENV_DUMP_FILE_PATH= $direnv dump | tee $cache/dump >\$DIRENV_DUMP_FILE_PATH\" \
  94    ${OFFLINE:+--option substituters ""}" &&
  95   find .cache/nix-shell -mindepth 1 -maxdepth 1 -not -name "$hash" -exec rm -rf {} + || {
  96     rm -rf "$PWD/.cache/nix-shell/$hash"
  97     log_error "cannot build shell.nix"
  98     return 1
  99   }
 100   } 3>$cache/dump
 101 fi