While the discussion about how to refactor test framework is not
finished (#1654), make this change: move `rm -rf build` in the
beginning of the test. For these reasons:
* it is useful to inspect the contents of the `build` directory
especially after the test failure
* if build crashes mid-test (e.g. process killed), next run should
not be affected by the `build` directory from the previous run
* add `strerror` function
* move `getErrno` to `System.Errno`
* use `strerror` in `Show FileError`
* on node there's no access to `strerror`, so `strerror` just converts the number to string
Convert `App.Control.Exception` interface to an alias to `HasErr`.
Probably `Exception` interface need to be deprecated or removed.
Note similar problem exists with `PrimIO` calling `PrimIO, Exception`,
also need to be fixed.
Fix this scenario:
```
throwBoth : Has [Exception String, Exception Int] es => App es ()
throwOne : Has [Exception Int] es => App es Int
throwOne {es} = handle {err = String} {e = es} throwBoth (\r => pure 1) (\e => pure 3)
```
With this commit it works, before this commit it failed with:
```
Error: While processing right hand side of throwOne. Can't find an implementation for Exception Int (String :: es).
TestException.idr:8:48--8:57
|
8 | throwOne {es} = handle {err = String} {e = es} throwBoth (\r => pure 1) (\e => pure 3)
| ^^^^^^^^^
```
On Unix-like operating systems stdio.h is usually line-buffered. As
putStr uses fputs(3) from stdio.h internally, output will be written to
standard out after a newline character is written to the buffer. Since
the prompt does not contain a newline, it will only be written to
standard output after the user presses return. I encountered this issue
on Alpine Linux which uses musl libc (instead of glibc). However, I
believe this issue is likely also reproducible with glibc. This commit
fixes this issue by flushing standard output after writing the prompt to
it. Surprisingly, `src/Idris/IDEMode/REPL.idr` already does this
correctly, `src/Idris/REPL.idr` does not though.
