Question: I have a runtime error that is happening at this line of code:

```
_searchresults = [_beerNames filteredArrayUsingPredicate:resultPredicate];

```

serchresuls is a NSArray (nil objects)
beerNames is a NSArray M (196 objects)
and result predicate is a NScomparison predicate and I don't really understand what that means
Here is my code for the result predicate

```
NSPredicate *resultPredicate = [NSPredicate predicateWithFormat:@"name contains[c] %@", searchText];

```

and searchText is a NSCF string, but it only fills up with one letter before the program crashes. 

The error it is giving me is this:

NSCFString 0x8cbce80> valueForUndefinedKey:]: this class is not key value coding-compliant for the key name.

Any ideas on what is going on?

Answer: 
In order to turn on numbered-sections in latex output you need to use `numbersections` in your YAML block. If you ever want to "discover" things like this with pandoc just poke around the templates:

```
 $ grep -i number default.latex
 $if(numbersections)$
 $ grep -i number default.html*
 $

```

As you can see this option does not work with html. 

Markdown and YAML I tested with:

```
 ---
 title: Test
 numbersections: true
 ---

 # blah

 Text is here.

 ## Double Blah

 Twice the text is here

```

If you need it to work with more than beamer,latex,context,opendoc you will need to file a bug at github.
In order to show section number in the produced output pdf, there are two choices.

### In YAML front matter

Add the following setting to begin of markdown file

```
---
numbersections: true
---

```

### In command line

We can also use the command option to generate pdf with numbered section. According to [Pandoc documentation](https://pandoc.org/MANUAL.html), the correct options is `--number-sections` or simply `-N`,

```
pandoc test.md -o test.pdf --number-sections
# pandoc test.md -o test.pdf -N

```