Question: I am trying to use the pigpen font <https://ctan.org/tex-archive/fonts/pigpen> by Oliver Corff.

The pigpen.tex file is *really* small and seems equivalent to the following:

```
\font\pp=pigpen

```

but the following won't produce a valid PDF using xetex

```
\font\pp=pigpen

{\pp HELLO WORLD}

\bye

```

> 
> `Sorry, pfa format not supported`
> 
> 
> 

What am I missing?

Answer: 
I made an experiment. I copied the `pigpen.pfa` file from

```
/usr/local/texlive/2022/texmf-dist/fonts/type1/public/pigpen/pigpen.pfa

```

to a working directory with the name `originalpigpen.pfa` and ran

```
t1binary originalpigpen.pfa -o pigpen.pfa

```

(yes, the produced PFB file with extension `.pfa`). Running your example file is now successful.

Now you can use the personal tree

```
mkdir -p $(kpsewhich -var-value=TEXMFHOME)/fonts/type1/public/pigpen
mv pigpen.pfa $(kpsewhich -var-value=TEXMFHOME)/fonts/type1/public/pigpen

```

and the PFB file masqueraded as PFA will be found with precedence over the distributed one.

[![enter image description here](https://i.stack.imgur.com/5z602.png)](https://i.stack.imgur.com/5z602.png)

I made a [query on the TeX Live list](https://tug.org/pipermail/tex-live/2022-November/048671.html), let's see what happens. The hack suggested above should be innocuous when the file format is changed at the distribution level.
The following worked for me in plain (Xe)TeX:

```
\input pigpen
\mypigpenfont
HELLO WORLD
\bye

```

[![Pigpen sample](https://i.stack.imgur.com/qduKt.png)](https://i.stack.imgur.com/qduKt.png)

It embeds a type 3 (bitmap) font, rather than a vector font.