lfe: add message to OTP version assertion

1 files changed, 4 insertions, 2 deletions

diff --git a/pkgs/development/interpreters/lfe/generic-builder.nix b/pkgs/development/interpreters/lfe/generic-builder.nix
index 6e74229e1e88a..5df491e72d3a1 100644
--- a/pkgs/development/interpreters/lfe/generic-builder.nix
+++ b/pkgs/development/interpreters/lfe/generic-builder.nix
@@ -9,7 +9,7 @@
 }:
 
 let
-  inherit (stdenv.lib) getVersion versionAtLeast versions;
+  inherit (stdenv.lib) assertMsg getVersion versionAtLeast versions;
 
   mainVersion = versions.major (getVersion erlang);
 
@@ -25,7 +25,9 @@ let
   };
 
 in
-assert versionAtLeast maximumOTPVersion mainVersion;
+assert (assertMsg (versionAtLeast maximumOTPVersion mainVersion)) ''
+  LFE ${version} is supported on OTP <=${maximumOTPVersion}, not ${mainVersion}.
+'';
 
 buildRebar3 {
   name = baseName;