Manual:$wgMaxTemplateDepth

Parser: $wgMaxTemplateDepth
Maximum recursion depth for templates within templates.
Introduced in version:1.12.0 (r29569)
Removed in version:still in use
Allowed values:(integer)
Default value:100 (1.38+)
40 (1.12-1.37)

Details edit

Maximum recursion depth for templates within templates. The current parser adds two levels to the PHP call stack for each template, and xdebug limits the call stack to 256 by default. So this should hopefully stop the parser before it hits the xdebug limit.

See also edit