Whoops first step is -1, so don't use that

README

@@ -26,8 +26,8 @@ Valid options are:
   -f    {int} Overwrite the CPU frequency (Hz) to be used for time measurements
   -g          Run with an external gravitational potential
   -G          Run with self-gravity
-  -n    {int} Execute a fixed number of time steps. Defaults to -1, which means
-              use the time_end parameter to stop. 
+  -n    {int} Execute a fixed number of time steps. When unset use the time_end
+              parameter to stop. 
   -s          Run with SPH
   -t    {int} The number of threads to use on each MPI rank. Defaults to 1 if not specified.
   -v     [12] Increase the level of verbosity 1: MPI-rank 0 writes 

examples/main.c

@@ -139,7 +139,7 @@ int main(int argc, char *argv[]) {
   int with_aff = 0;
   int dry_run = 0;
   int dump_tasks = 0;
-  int nsteps = -1;
+  int nsteps = -2;
   int with_cosmology = 0;
   int with_external_gravity = 0;
   int with_self_gravity = 0;