# Weird behaviour/bug with pi and rational exponents

When I type this:

```
print numerical_approx((4/pi())^(2/1))
print numerical_approx((4/3.14159265358979)^(2/1))
```

I get

```
sage: 3.90303389783585e2585827972
1.62113893827741
```

(note the letter "e" in the 1st line)

This happens on my notebook, on the COCALC server there is a crash.

Has anyone else seen this ? What is the problem there ?

I can reproduce this in the Sage REPL of Python3-based Sage 8.8.beta3 on macOS too.

Minimal example:

`(4/pi)^2`

and`(4/I)^(2/1)`

work fine but`(4/pi)^(2/1)`

and`(4/e)^(2/1)`

misbehave, going into some intense long-lasting computation. Interrupting this long computation givesEven more minimal

`(2/pi)^(2/1)`

:-) This looks like a bug in Pynac/Ginac that is called for constructing the string representation