title: Error in eval(expr, envir, enclos): no loop for break/next, jumping to top level
body: <p>I am trying to run a stepwise analysis on a negative binomial model with many factors:</p>
  
  <pre><code>step(glm.nb(totphy~lat+long+elev+cult+poll+blkage+canden+irr+dust+dustcon+mid+herb+miteprob+ermprob+tsmprob+mcdprob+brprob+armprob+mitapp+acra+agri+carz+envi+fujim+next+vend+zeal+cover+orchtype+pestint+mating+ties+rimon+igr+lime+naa+sevin+land+area+ermpres+tsmpres+mcdpres+armpres+zmalipres+ltemp+lmaxtemp+lmintemp+ldewp+lrh+lwindsp+lwinddir+lsolar+lprecip+lleaf+lsoil,data=mites), direction="forward", criterion=aic)
  </code></pre>
  
  <p>This code works if I only include the variables up to "fujim", adding more variables causes this error:</p>
  
  <pre><code>Error in eval(expr, envir, enclos) : 
    no loop for break/next, jumping to top level
  </code></pre>
  
  <p>I am fairly unfamiliar with R, so what does this mean?</p>