Fail better when run under /bin/sh.

lib/assert-decent-shell

@@ -0,0 +1,15 @@
+[ -n "$ZSH_VERSION" ] && return 0
+if [ -n "$BASH_VERSION" ]; then
+    # TODO: Find a cleaner way to detect if bash is running as 'sh'.
+    ps $$ | grep bash >/dev/null 2>&1 && return 0
+fi
+
+echo "Attempt to run from some shell we don't (yet?) support."
+if type pstree >/dev/null 2>&1; then
+    pstree -h
+else
+    ps ajhf
+fi
+return 1
+
+# vim:ft=sh

lib/basics

@@ -1,3 +1,5 @@
+source ~/.../lib/assert-decent-shell || return
+
 PATH="$HOME/.../bin:$PATH" # needed to bootsrap
 eval `... env`
 source ~/.../lib/tracefuncs

lib/path-manip

@@ -1,6 +1,8 @@
 # This bash/zsh library contains useful functions for viewing and manipulating
 # your PATH environment variable, and other similar environment variables.
 
+source ~/.../lib/assert-decent-shell || return
+
 source ~/.../lib/tracefuncs
 
 # List each directory in your PATH, one per line

lib/path-manip.sh

@@ -1,5 +1,8 @@
 # (Here for backwards compatibility. This is not actually a /bin/sh script, so
 # the .sh name isn't quite right.)
+
+source ~/.../lib/assert-decent-shell || return
+
 source ~/.../lib/path-manip
 alias path-list=...path-list
 alias path-remove=...path-remove

lib/scripting

@@ -1,3 +1,5 @@
+source ~/.../lib/assert-decent-shell || return
+
 source "$HOME/.../lib/tracefuncs"
 function ...repo {
     if [ -z "$1" ]; then

lib/set-shellname

@@ -1,3 +1,5 @@
+source ~/.../lib/assert-decent-shell || return
+
 if [ -n "$ZSH_VERSION" ]; then
     export SHELLNAME=zsh
 elif [ -n "$BASH_VERSION" ]; then

lib/tracefuncs

@@ -1,3 +1,5 @@
+source ~/.../lib/assert-decent-shell || return
+
 function ...istracing {
     [[ -n "$DOTDOTDOT_TRACE" ]]
 }