.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 src in $nixshell_sources
  64 do watch_file "$src"; 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 $cache/"
  71   {
  72   flock --shared 3
  73   direnv_watches=$DIRENV_WATCHES
  74   # Load the cached environment
  75   direnv_load sh -c "cat >\$DIRENV_DUMP_FILE_PATH $cache/dump"
  76   # Restore DIRENV_WATCHES to prevent infinite reload
  77   # when a watched file is touched without being modified
  78   # and thus without changing $hash.
  79   DIRENV_WATCHES=$direnv_watches
  80   #{ printf "\x1f\x8b\x08\x00\x00\x00\x00\x00"; echo $DIRENV_WATCHES | tr _- /+ | base64 -d; } | gzip -dc
  81   # Re-run the shellHook to update envvars like GPG_TTY,
  82   # and run gpg-connect-agent updatestartuptty /bye
  83   eval "$shellHook"
  84   } 3<"$cache"/dump
  85 else
  86   log_status "building $cache/"
  87   mkdir -p "$cache"
  88   {
  89   flock --exclusive 3
  90   # Register the derivation as a root for the garbage-collector,
  91   # then cache a dump of the environment from within the nix-shell,
  92   # then unregister previous derivations,
  93   # then load the cached environment.
  94   nix-instantiate >/dev/null ./shell.nix --indirect --add-root "$cache"/shell.drv \
  95    ${TRACE:+--show-trace} \
  96    ${OFFLINE:+--option substituters ""} &&
  97   nix-store >/dev/null --indirect --add-root "$cache"/shell.dep \
  98    --realise $(nix-store --query --references "$cache"/shell.drv) \
  99    ${OFFLINE:+--option substituters ""} &&
 100   direnv_load sh -c "nix-shell ${TRACE:+--show-trace} \
 101    --run \"DIRENV_DUMP_FILE_PATH= $direnv dump | tee $cache/dump >\$DIRENV_DUMP_FILE_PATH\" \
 102    ${OFFLINE:+--option substituters ""}" &&
 103   find .cache/nix-shell -mindepth 1 -maxdepth 1 -not -name "$hash" -exec rm -rf {} + || {
 104     rm -rf "$PWD/.cache/nix-shell/$hash"
 105     log_error "cannot build shell.nix"
 106     return 1
 107   }
 108   } 3>"$cache"/dump
 109 fi