From 1862868a357950e86fe93d776aeb35494441e99b Mon Sep 17 00:00:00 2001
From: kalmar <kalmar@amu.edu.pl>
Date: Mon, 24 Jul 2017 22:50:52 +0200
Subject: [PATCH] more verbose throws in divexact

---
 src/GroupRings.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/GroupRings.jl b/src/GroupRings.jl
index bf3e173..45bae20 100644
--- a/src/GroupRings.jl
+++ b/src/GroupRings.jl
@@ -432,11 +432,11 @@ end
 
 function divexact{T}(X::GroupRingElem{T}, Y::GroupRingElem{T})
    if length(Y) != 1
-      throw("Can not divide by a non-primitive element $(Y)!")
+      throw("Can not divide by a non-primitive element: $(Y)!")
    else
       idx = findfirst(Y)
       c = Y[idx]
-      c == 0 || throw("Can not invert")
+      c != 0 || throw("Can not invert: $c not found in $Y")
       g = parent(Y).basis[idx]
       return X*1//c*parent(Y)(inv(g))
    end