Nix build is broken (2019/11/20)

[szg251]

I use postgresql-typed in one of my projects. When used with stack, it works perfectly, but when I tried to migrate to nix, it seems to be broken. The package itself is marked as broken in the nixpkgs. If I ignore the warning, I get the following error message:

test/Main.hs:1:1: error:
    Exception when trying to run compile-time code:
      Network.Socket.connect: <socket: 12>: does not exist (No such file or directory)
    Code: template-haskell-2.14.0.0:Language.Haskell.TH.Quote.quoteDec
            pgSQL "!CREATE TYPE myenum AS enum ('abc', 'DEF', 'XX_ye')"
  |
1 | {-# LANGUAGE OverloadedStrings, FlexibleInstances, MultiParamTypeClasses, DataKinds, DeriveDataTypeable, TypeFamilies, PatternGuards, StandaloneDeriving #-}
  | ^

builder for '/nix/store/ghbmalyqp9511ps05f6c7mvx5d6wwpnk-postgresql-typed-0.6.1.0.drv' failed with exit code 1

My guess is that, some post build scripts need a running postgres server.

Nixpkgs rev: 58fb23f72ad916c8bbfa3c3bc2d0c83c9cfcdd16

[albertov]

Your guess is right. The building and running the tests require a running postgres server. A quick workaround is to disable the package's tests in a nix overlay.

Nix is used to test postgresql-typed in CI so you can also take a look at https://github.com/dylex/postgresql-typed/blob/master/nix/default.nix and

postgresql-typed/nix/utilities.nix

Lines 93 to 165 in 4ef29b9

	withPostgres = pg: drv:
	let functions = ''
	${trapMagic}
	function initPG() {
	${super.lib.optionalString super.stdenv.isDarwin "export TMPDIR=/tmp"}
	${super.lib.optionalString (!super.stdenv.isDarwin) "export LANG=C.UTF-8"}
	${super.lib.optionalString (!super.stdenv.isDarwin) "export LC_ALL=C.UTF-8"}
	${super.lib.optionalString (!super.stdenv.isDarwin) "export LC_CTYPE=C.UTF-8"}
	export TZ='UTC'
	export PGHOST=$(mktemp -d)
	export PGDATA=$PGHOST/db
	export PGPORT=5433
	export PGSOCK=$PGHOST/.s.PGSQL.$PGPORT
	export PGDATABASE=templatepg
	export PGUSER=templatepg
	# We set these environment variables so postgresql-typed knows how
	# to connect to the database at compile-time to make sure all SQL
	# queries are well typed and well formed
	export TPG_SOCK=$PGSOCK
	export TPG_DB=$PGDATABASE
	export TPG_USER=$PGUSER
	#
	${pg}/bin/initdb -E UTF8 $PGDATA
	# avoid conflicts on travis and elsewhere
	echo "port = $PGPORT" >> $PGDATA/postgresql.conf
	${pg}/bin/postgres -D $PGDATA -k $PGHOST &
	echo -n "Waiting for database to start up..."
	while [[ ! -e $PGSOCK ]]; do sleep 0.1; done
	${pg}/bin/createuser -h $PGHOST -U $(id -u --name) -s $PGUSER
	${pg}/bin/createdb -h $PGHOST -O $PGUSER $PGDATABASE
	echo "Created database PGDATABASE=$PGDATABASE at PGHOST=$PGHOST."
	echo "Call killPG to stop and delete it. Call initPG to re-create it"
	}
	function killPG() {
	echo "Killing postgres database at $PGHOST"
	pg_ctl stop || true
	echo "Waiting for postgres database to die ..."
	while [[ -e $PGSOCK ]]; do sleep 0.1; done
	echo "Postgres is dead, deleting its data dir"
	rm -rf $PGHOST
	}
	function reinitPG {
	killPG && initPG
	}
	# export the functions so they're available in the development nix-shell
	# so the database can be re-created easly
	export -f initPG
	export -f killPG
	export -f reinitPG
	trap_prepend "killPG" EXIT
	'';
	in super.haskell.lib.overrideCabal drv (old: {
	buildDepends = (old.buildDepends or []) ++ [ pg ];
	preBuild = ''
	${old.preBuild or ""}
	${functions}
	initPG
	'';
	shellHook = ''
	${old.shellHook or ""}
	${functions}
	initPG
	'';
	postInstall = ''
	killPG
	${old.postInstall or ""}
	'';
	});
	};

to see how a running postgres can be created to run the tests using Nix instead of disabling them.

[szg251]

Thank you for the prompt reply. I'll try to start a postgres server with nix.

See databrary for some notes about starting a postgres instance in nix