Add note to documentation about using spaces instead of tabs for indentation, as YAML does not allow tabs (#199).

NEWS

@@ -1,3 +1,7 @@
+1.3.13.dev0
+ * #199: Add note to documentation about using spaces instead of tabs for indentation, as YAML does
+   not allow tabs.
+
 1.3.12
  * Only log to syslog when run from a non-interactive console (e.g. a cron job).
  * Remove unicode byte order mark from syslog output so it doesn't show up as a literal in rsyslog

docs/how-to/set-up-backups.md

@@ -71,7 +71,8 @@ to ignore anything you don't need.
 Note that the configuration file is organized into distinct sections, each
 with a section name like `location:` or `storage:`. So take care that if you
 uncomment a particular option, also uncomment its containing section name, or
-else borgmatic won't recognize the option.
+else borgmatic won't recognize the option. Also be sure to use spaces rather
+than tabs for indentation; YAML does not allow tabs.
 
 You can also get the same sample configuration file from the [configuration
 reference](https://torsion.org/borgmatic/docs/reference/configuration.md), the authoritative set of
@@ -212,6 +213,22 @@ section of configuration.
 
 ## Troubleshooting
 
+### "found character that cannot start any token" error
+
+If you run borgmatic and see an error looking something like this, it probably
+means you've used tabs instead of spaces:
+
+```console
+test.yaml: Error parsing configuration file
+An error occurred while parsing a configuration file at test.yaml:
+while scanning for the next token
+found character that cannot start any token
+  in "test.yaml", line 230, column 1
+```
+
+YAML does not allow tabs. So to fix this, simply replace any tabs in your
+configuration file with the requisite number of spaces.
+
 ### libyaml compilation errors
 
 borgmatic depends on a Python YAML library (ruamel.yaml) that will optionally

setup.py

@@ -1,6 +1,6 @@
 from setuptools import find_packages, setup
 
-VERSION = '1.3.12'
+VERSION = '1.3.13.dev0'
 
 
 setup(