+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+# This is a single file library, just source this file. When an error
+# happens, we print a stack trace then exit. In an interactive shell, we
+# return from functions instead of exiting. If err-cleanup is a command,
+# it runs before the stack trace. Functions are documented inline below
+# for additional use cases.
+#
+# Note: occasionally the line numbers are off a bit (at least in Bash
+# 5.0). This appears to be a bash bug. I plan to report it next time it
+# happens to me.
+#
+# Please email me if you use this or have anything to contribute. I'm
+# not aware of any users yet Ian Kelling <ian@iankelling.org>.
+#
+# Tested on bash 4.4.20(1)-release (x86_64-pc-linux-gnu) and
+# 5.0.17(1)-release (x86_64-pc-linux-gnu).
+#
+# Related: see my bash script template repo at https://iankelling.org/git.
+
+
+# TODO: investigate to see if we can format output betting in case of
+# subshell failure. Right now, we get independent trace from inside and
+# outside of the subshell. Note, errexit + inherit_errexit doesn't have
+# any smarts around this either.