On new repositories ./hg/branch and .hg/dirstate do not exist. In this case use "hg summary"

themes/base.theme.bash

@@ -160,10 +160,19 @@ function hg_prompt_vars {
 
     HG_ROOT=$(get_hg_root)
 
+    if [ -f $HG_ROOT/branch ]; then
         # Mercurial holds it's current branch in .hg/branch file    
         SCM_BRANCH=$(cat $HG_ROOT/branch)
+    else
+        SCM_BRANCH=$(hg summary 2> /dev/null | grep branch: | awk '{print $2}')
+    fi
+
+    if [ -f $HG_ROOT/dirstate ]; then
         # Mercurial holds various information about the working directory in .hg/dirstate file. More on http://mercurial.selenic.com/wiki/DirState
         SCM_CHANGE=$(hexdump -n 10 -e '1/1 "%02x"' $HG_ROOT/dirstate | cut -c-12)
+    else
+        SCM_CHANGE=$(hg summary 2> /dev/null | grep parent: | awk '{print $2}')
+    fi
 }
 
 function rvm_version_prompt {