From curl 8.12 through 8.16, config files could slice variable values and include other config files without an explicit depth cap. Together, these features let curl simulate any two-counter Minsky program. Under the usual idealization of unbounded strings and resources, this construction was Turing-complete.
Curl 8.17.0 added a five-level include cap that breaks this reduction.
↫ Nicolas Seriot
Neat.
