diff --git a/lib/diagnostics.zsh b/lib/diagnostics.zsh
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+# diagnostics.zsh
+#
+# Diagnostic and debugging support for oh-my-zsh
+
+# omz_diagnostic_dump()
+#
+# Author: Andrew Janke <andrew@apjanke.net>
+#
+# Usage:
+#
+# omz_diagnostic_dump [-v] [-V] [file]
+#
+# NOTE: This is a work in progress. Its interface and behavior are going to change,
+# and probably in non-back-compatible ways.
+#
+# Outputs a bunch of information about the state and configuration of
+# oh-my-zsh, zsh, and the user's system. This is intended to provide a
+# bunch of context for diagnosing your own or a third party's problems, and to
+# be suitable for posting to public bug reports.
+#
+# The output is human-readable and its format may change over time. It is not
+# suitable for parsing. All the output is in one single file so it can be posted
+# as a gist or bug comment on GitHub. GitHub doesn't support attaching tarballs
+# or other files to bugs; otherwise, this would probably have an option to produce
+# tarballs that contain copies of the config and customization files instead of
+# catting them all in to one file.
+#
+# This is intended to be widely portable, and run anywhere that oh-my-zsh does.
+# Feel free to report any portability issues as bugs.
+#
+# This is written in a defensive style so it still works (and can detect) cases when
+# basic functionality like echo and which have been redefined. In particular, almost
+# everything is invoked with "builtin" or "command", to work in the face of user 
+# redefinitions.
+#
+# OPTIONS
+#
+# [file]   Specifies the output file. If not given, a file in the current directory
+#        is selected automatically.
+#
+# -v    Increase the verbosity of the dump output. May be specified multiple times.
+#       Verbosity levels:
+#        0 - Basic info, shell state, omz configuration, git state
+#        1 - (default) Adds key binding info and configuration file contents
+#        2 - Adds zcompdump file contents
+#
+# -V    Reduce the verbosity of the dump output. May be specified multiple times.
+#
+# TODO:
+# * Multi-file capture
+# * Add automatic gist uploading
+# * Consider whether to move default output file location to TMPDIR. More robust
+#     but less user friendly.
+#
+function omz_diagnostic_dump() {
+  emulate -L zsh
+
+  local thisfcn=omz_diagnostic_dump
+  local -A opts
+  local opt_verbose opt_noverbose opt_outfile
+  local timestamp=$(date +%Y%m%d-%H%M%S)
+  local outfile=omz_diagdump_$timestamp.txt
+  builtin zparseopts -A opts -D -- "v+=opt_verbose" "V+=opt_noverbose"
+  local verbose n_verbose=${#opt_verbose} n_noverbose=${#opt_noverbose}
+  (( verbose = 1 + n_verbose - n_noverbose ))
+
+  if [[ ${#*} > 0 ]]; then
+    opt_outfile=$1
+  fi
+  if [[ ${#*} > 1 ]]; then
+    builtin echo "$thisfcn: error: too many arguments" >&2
+    return 1
+  fi
+  if [[ -n "$opt_outfile" ]]; then
+    outfile="$opt_outfile"
+  fi
+
+  # Always write directly to a file so terminal escape sequences are
+  # captured cleanly
+  _omz_diag_dump_one_big_text &> "$outfile"
+  if [[ $? != 0 ]]; then
+    builtin echo "$thisfcn: error while creating diagnostic dump; see $outfile for details"
+  fi
+
+  builtin echo
+  builtin echo Diagnostic dump file created at: "$outfile"
+  builtin echo
+  builtin echo To share this with OMZ developers, post it as a gist on GitHub 
+  builtin echo at "https://gist.github.com" and share the link to the gist.
+  builtin echo
+  builtin echo "WARNING: This dump file contains all your zsh and omz configuration files,"
+  builtin echo "so don't share it publicly if there's sensitive information in them."
+  builtin echo
+
+}
+
+function _omz_diag_dump_one_big_text() {
+  local program programs progfile md5
+
+  builtin echo oh-my-zsh diagnostic dump
+  builtin echo
+
+  # Basic system and zsh information
+  command date
+  command uname -a
+  builtin echo OSTYPE=$OSTYPE
+  command zsh --version
+  builtin echo User: $USER
+  builtin echo
+
+  # Installed programs
+  programs=(sh zsh ksh bash sed cat grep find git posh)
+  for program in $programs; do
+    local md5_str="" md5="" link_str="" extra_str=""
+    progfile=$(builtin which $program)
+    if [[ $? == 0 ]]; then
+      if [[ -e $progfile ]]; then
+        if builtin whence md5 &>/dev/null; then
+          extra_str+=" $(md5 -q $progfile)"
+        fi
+        if [[ -h "$progfile" ]]; then
+          extra_str+=" ( -> ${file:A} )"
+        fi
+      fi
+      builtin printf '%-9s %-20s %s\n' "$program is" "$progfile" "$extra_str"
+    else
+      builtin echo "$program: not found"
+    fi
+  done
+  builtin echo
+  builtin echo Versions:
+  builtin echo "zsh: $(zsh --version)"
+  builtin echo "bash: $(bash --version | command grep bash)"
+  builtin echo "git: $(git --version)"
+  builtin echo "grep: $(grep --version)"
+  builtin echo
+
+  # Core command definitions
+  _omz_diag_dump_check_core_commands || return 1
+  builtin echo  
+
+  # ZSH Process state
+  builtin echo Process state:
+  builtin echo pwd: $PWD
+  if builtin whence pstree &>/dev/null; then
+    builtin echo Process tree for this shell:
+    pstree -p $$
+  else
+    ps -fT
+  fi
+  builtin set | command grep -a '^\(ZSH\|plugins\|TERM\|LC_\|LANG\|precmd\|chpwd\|preexec\|FPATH\|TTY\|DISPLAY\|PATH\)\|OMZ'
+  builtin echo
+  #TODO: Should this include `env` instead of or in addition to `export`?
+  builtin echo Exported:
+  builtin echo $(builtin export | command sed 's/=.*//')
+  builtin echo 
+  builtin echo Locale:
+  command locale
+  builtin echo
+
+  # Zsh configuration
+  builtin echo Zsh configuration:
+  builtin echo setopt: $(builtin setopt)
+  builtin echo
+
+  # Oh-my-zsh installation
+  builtin echo oh-my-zsh installation:
+  command ls -ld ~/.z*
+  command ls -ld ~/.oh*
+  builtin echo
+  builtin echo oh-my-zsh git state:
+  (cd $ZSH && builtin echo "HEAD: $(git rev-parse HEAD)" && git remote -v && git status | command grep "[^[:space:]]")
+  if [[ $verbose -ge 1 ]]; then
+    (cd $ZSH && git reflog --date=default | command grep pull)
+  fi
+  builtin echo
+  if [[ -e $ZSH_CUSTOM ]]; then
+    local custom_dir=$ZSH_CUSTOM
+    if [[ -h $custom_dir ]]; then
+      custom_dir=$(cd $custom_dir && pwd -P)
+    fi
+    builtin echo "oh-my-zsh custom dir:"
+    builtin echo "   $ZSH_CUSTOM ($custom_dir)"
+    (cd ${custom_dir:h} && command find ${custom_dir:t} -name .git -prune -o -print)
+    builtin echo
+  fi
+
+  # Key binding and terminal info
+  if [[ $verbose -ge 1 ]]; then
+    builtin echo "bindkey:"
+    builtin bindkey
+    builtin echo
+    builtin echo "infocmp:"
+    command infocmp
+    builtin echo
+  fi
+
+  # Configuration file info
+  local zdotdir=${ZDOTDIR:-$HOME}
+  builtin echo "Zsh configuration files:"
+  local cfgfile cfgfiles
+  cfgfiles=( /etc/zshenv /etc/zprofile /etc/zshrc /etc/zlogin /etc/zlogout 
+    $zdotdir/.zshenv $zdotdir/.zprofile $zdotdir/.zshrc $zdotdir/.zlogin $zdotdir/.zlogout )
+  command ls -lad $cfgfiles 2>&1
+  builtin echo
+  if [[ $verbose -ge 1 ]]; then
+    for cfgfile in $cfgfiles; do
+      _omz_diag_dump_echo_file_w_header $cfgfile
+    done
+  fi
+  builtin echo "Zsh compdump files:"
+  local dumpfile dumpfiles
+  command ls -lad $zdotdir/.zcompdump*
+  dumpfiles=( $zdotdir/.zcompdump*(N) )
+  if [[ $verbose -ge 2 ]]; then
+    for dumpfile in $dumpfiles; do
+      _omz_diag_dump_echo_file_w_header $dumpfile
+    done
+  fi
+
+}
+
+function _omz_diag_dump_check_core_commands() {
+  builtin echo "Core command check:"
+  local redefined name builtins externals
+  redefined=()
+  # All the zsh non-module builtin commands
+  # These are taken from the zsh reference manual for 5.0.2
+  # Commands from modules should not be included.
+  # (For back-compatibility, if any of these are newish, they should be removed,
+  # or at least made conditional on the version of the current running zsh.)
+  # "history" is also excluded because OMZ is known to redefine that
+  builtins=( alias autoload bg bindkey break builtin bye cd chdir command
+    comparguments compcall compctl compdescribe compfiles compgroups compquote comptags
+    comptry compvalues continue declare dirs disable disown echo echotc echoti emulate
+    enable eval exec exit export false fc fg float functions getln getopts hash
+    integer jobs kill let limit local log logout noglob popd print printf
+    pushd pushln pwd r read readonly rehash return sched set setopt shift
+    source suspend test times trap true ttyctl type typeset ulimit umask unalias
+    unfunction unhash unlimit unset unsetopt vared wait whence where which zcompile
+    zle zmodload zparseopts zregexparse zstyle )
+  builtins_fatal=( builtin command local )
+  externals=( zsh )
+  for name in $builtins; do
+    if [[ $(builtin whence -w $name) != "$name: builtin" ]]; then
+      builtin echo "builtin '$name' has been redefined"
+      builtin which $name
+      redefined+=$name
+    fi
+  done
+  for name in $externals; do
+    if [[ $(builtin whence -w $name) != "$name: command" ]]; then
+      builtin echo "command '$name' has been redefined"
+      builtin which $name
+      redefined+=$name
+    fi
+  done
+
+  if [[ -n "$redefined" ]]; then
+    builtin echo "SOME CORE COMMANDS HAVE BEEN REDEFINED: $redefined"
+  else
+    builtin echo "All core commands are defined normally"
+  fi
+
+}
+
+function _omz_diag_dump_echo_file_w_header() {
+  local file=$1
+  if [[ ( -f $file || -h $file ) ]]; then
+    builtin echo "========== $file =========="
+    if [[ -h $file ]]; then
+      builtin echo "==========    ( => ${file:A} )   =========="
+    fi
+    command cat $file
+    builtin echo "========== end $file =========="
+    builtin echo
+  fi
+}
+
+