home-manager/modules/lib-bash/activation-init.sh
Robert Helgesson dcbe0f2a31
home-manager: add activation sanity check of Nix
This adds an empty `nix-build` command to verify that the user is
having a good Nix install. It also, as a side effect, will create the
necessary per-user `profiles` and `gcroots` directories.

Fixes #1246
2020-05-20 22:32:35 +02:00

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2.5 KiB
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#!/usr/bin/env bash
function setupVars() {
local profilesPath="/nix/var/nix/profiles/per-user/$USER"
local gcPath="/nix/var/nix/gcroots/per-user/$USER"
genProfilePath="$profilesPath/home-manager"
newGenPath="@GENERATION_DIR@";
newGenGcPath="$gcPath/current-home"
local greatestGenNum
greatestGenNum=$( \
nix-env --list-generations --profile "$genProfilePath" \
| tail -1 \
| sed -E 's/ *([[:digit:]]+) .*/\1/')
if [[ -n $greatestGenNum ]] ; then
oldGenNum=$greatestGenNum
newGenNum=$((oldGenNum + 1))
else
newGenNum=1
fi
if [[ -e $profilesPath/home-manager ]] ; then
oldGenPath="$(readlink -e "$profilesPath/home-manager")"
fi
$VERBOSE_ECHO "Sanity checking oldGenNum and oldGenPath"
if [[ -v oldGenNum && ! -v oldGenPath
|| ! -v oldGenNum && -v oldGenPath ]]; then
errorEcho "Invalid profile number and current profile values! These"
errorEcho "must be either both empty or both set but are now set to"
errorEcho " '${oldGenNum:-}' and '${oldGenPath:-}'"
errorEcho "If you don't mind losing previous profile generations then"
errorEcho "the easiest solution is probably to run"
errorEcho " rm $profilesPath/home-manager*"
errorEcho " rm $gcPath/current-home"
errorEcho "and trying home-manager switch again. Good luck!"
exit 1
fi
}
if [[ -v VERBOSE ]]; then
export VERBOSE_ECHO=echo
export VERBOSE_ARG="--verbose"
else
export VERBOSE_ECHO=true
export VERBOSE_ARG=""
fi
echo "Starting home manager activation"
# Verify that we can connect to the Nix store and/or daemon. This will
# also create the necessary directories in profiles and gcroots.
$VERBOSE_ECHO "Sanity checking Nix"
nix-build --expr '{}' --no-out-link
setupVars
if [[ -v DRY_RUN ]] ; then
echo "This is a dry run"
export DRY_RUN_CMD=echo
else
$VERBOSE_ECHO "This is a live run"
export DRY_RUN_CMD=""
fi
if [[ -v VERBOSE ]]; then
echo -n "Using Nix version: "
nix-env --version
fi
$VERBOSE_ECHO "Activation variables:"
if [[ -v oldGenNum ]] ; then
$VERBOSE_ECHO " oldGenNum=$oldGenNum"
$VERBOSE_ECHO " oldGenPath=$oldGenPath"
else
$VERBOSE_ECHO " oldGenNum undefined (first run?)"
$VERBOSE_ECHO " oldGenPath undefined (first run?)"
fi
$VERBOSE_ECHO " newGenPath=$newGenPath"
$VERBOSE_ECHO " newGenNum=$newGenNum"
$VERBOSE_ECHO " newGenGcPath=$newGenGcPath"
$VERBOSE_ECHO " genProfilePath=$genProfilePath"