From f7696c66e85008e2b60a579bcdf5ff13c141d0af Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Sat, 8 Aug 2020 15:48:51 +0000
Subject: [PATCH] Fix perl FFI for floating ca derivations

Path is null when not known statically.
---
 perl/lib/Nix/Store.xs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/perl/lib/Nix/Store.xs b/perl/lib/Nix/Store.xs
index de60fb939..6fe01fff0 100644
--- a/perl/lib/Nix/Store.xs
+++ b/perl/lib/Nix/Store.xs
@@ -303,11 +303,15 @@ SV * derivationFromPath(char * drvPath)
             hash = newHV();
 
             HV * outputs = newHV();
-            for (auto & i : drv.outputs)
+            for (auto & i : drv.outputs) {
+                auto pathOpt = i.second.pathOpt(*store(), drv.name);
                 hv_store(
                     outputs, i.first.c_str(), i.first.size(),
-                    newSVpv(store()->printStorePath(i.second.path(*store(), drv.name)).c_str(), 0),
+                    !pathOpt
+                        ? newSV(0) /* null value */
+                        : newSVpv(store()->printStorePath(*pathOpt).c_str(), 0),
                     0);
+            }
             hv_stores(hash, "outputs", newRV((SV *) outputs));
 
             AV * inputDrvs = newAV();