buildenv: support very long `paths`

1 files changed, 11 insertions, 1 deletions

diff --git a/pkgs/build-support/buildenv/builder.pl b/pkgs/build-support/buildenv/builder.pl
index fd8098caf13..155af314397 100755
--- a/pkgs/build-support/buildenv/builder.pl
+++ b/pkgs/build-support/buildenv/builder.pl
@@ -117,10 +117,20 @@ sub addPkg {
     }
 }
 
+# Read packages list.
+my $pkgs;
+
+if (exists $ENV{"pkgsPath"}) {
+    open FILE, $ENV{"pkgsPath"};
+    $pkgs = <FILE>;
+    close FILE;
+} else {
+    $pkgs = $ENV{"pkgs"}
+}
 
 # Symlink to the packages that have been installed explicitly by the
 # user.
-for my $pkg (@{decode_json $ENV{"pkgs"}}) {
+for my $pkg (@{decode_json $pkgs}) {
     for my $path (@{$pkg->{paths}}) {
         addPkg($path, $ENV{"ignoreCollisions"} eq "1", $pkg->{priority}) if -e $path;
     }