From c502831a1d087a406e80dede8cf14e3e97531006 Mon Sep 17 00:00:00 2001
From: Graham Christensen <graham@grahamc.com>
Date: Wed, 1 Jan 2020 20:50:40 -0500
Subject: [PATCH] exportReferencesGraph: support working

Before, we would get:

    [deploy@bastion:~]$ nix-store -r /nix/store/grfnl76cahwls0igd2by2pqv0dimi8h2-nixos-system-eris-19.09.20191213.03f3def.drv
    these derivations will be built:
      /nix/store/3ka4ihvwh6wsyhpd2qa9f59506mnxvx1-initrd-linux-4.19.88.drv
      /nix/store/ssxwmll7v21did1c8j027q0m8w6pg41i-unit-prometheus-alertmanager-irc-notifier.service.drv
      /nix/store/mvyvkj46ay7pp7b1znqbkck2mq98k0qd-unit-script-network-local-commands-start.drv
      /nix/store/vsl1y9mz38qfk6pyirjwnfzfggz5akg6-unit-network-local-commands.service.drv
      /nix/store/wi5ighfwwb83fdmav6z6n2fw6npm9ffl-unit-prometheus-hydra-exporter.service.drv
      /nix/store/x0qkv535n75pbl3xn6nn1w7qkrg9wwyg-unit-prometheus-packet-sd.service.drv
      /nix/store/lv491znsjxdf51xnfxh9ld7r1zg14d52-unit-script-packet-sd-env-key-pre-start.drv
      /nix/store/nw4nzlca49agsajvpibx7zg5b873gk9f-unit-script-packet-sd-env-key-start.drv
      /nix/store/x674wwabdwjrkhnykair4c8mpxa9532w-unit-packet-sd-env-key.service.drv
      /nix/store/ywivz64ilb1ywlv652pkixw3vxzfvgv8-unit-wireguard-wg0.service.drv
      /nix/store/v3b648293g3zl8pnn0m1345nvmyd8dwb-unit-script-acme-selfsigned-status.nixos.org-start.drv
      /nix/store/zci5d3zvr6fgdicz6k7jjka6lmx0v3g4-unit-acme-selfsigned-status.nixos.org.service.drv
      /nix/store/f6pwvnm63d0kw5df0v7sipd1rkhqxk5g-system-units.drv
      /nix/store/iax8071knxk9c7krpm9jqg0lcrawf4lc-etc.drv
      /nix/store/grfnl76cahwls0igd2by2pqv0dimi8h2-nixos-system-eris-19.09.20191213.03f3def.drv
    error: invalid file name 'closure-init-0' in 'exportReferencesGraph'

This was tough to debug, I didn't figure out which one was broken until I did:

    nix-store -r /nix/store/grfnl76cahwls0igd2by2pqv0dimi8h2-nixos-system-eris-19.09.20191213.03f3def.drv 2>&1 | grep  nix/store | xargs -n1 nix-store -r

and then looking at the remaining build graph:

    $ nix-store -r /nix/store/grfnl76cahwls0igd2by2pqv0dimi8h2-nixos-system-eris-19.09.20191213.03f3def.drv
    these derivations will be built:
      /nix/store/3ka4ihvwh6wsyhpd2qa9f59506mnxvx1-initrd-linux-4.19.88.drv
      /nix/store/grfnl76cahwls0igd2by2pqv0dimi8h2-nixos-system-eris-19.09.20191213.03f3def.drv
    error: invalid file name 'closure-init-0' in 'exportReferencesGraph'

and knowing the initrd build is before the system, then:

    $ nix show-derivation /nix/store/3ka4ihvwh6wsyhpd2qa9f59506mnxvx1-initrd-linux-4.19.88.drv
    {
      "/nix/store/3ka4ihvwh6wsyhpd2qa9f59506mnxvx1-initrd-linux-4.19.88.drv": {
        [...]
        "exportReferencesGraph": "closure-init-0 /nix/store/...-stage-1-init.sh closure-mdadm.conf-1 /nix/store/...-mdadm.conf closure-ubuntu.conf-2 ...",
        [...]
      }
    }

I then searched the repo for "in 'exportReferencesGraph'", found this
recently updated regex, and realized it was missing a "-".
---
 src/libstore/build.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index de0ce9ae1..5d681d279 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1985,7 +1985,7 @@ void DerivationGoal::startBuilder()
             throw BuildError(format("odd number of tokens in 'exportReferencesGraph': '%1%'") % s);
         for (Strings::iterator i = ss.begin(); i != ss.end(); ) {
             string fileName = *i++;
-            static std::regex regex("[A-Za-z_][A-Za-z0-9_.]*");
+            static std::regex regex("[A-Za-z_][A-Za-z0-9_.-]*");
             if (!std::regex_match(fileName, regex))
                 throw Error("invalid file name '%s' in 'exportReferencesGraph'", fileName);