Source code does not show for crystal eval compilation errors

[HertzDevil]

Since the standard input and the command-line argument "files" do not correspond to actual files and they do not originate from a macro expansion, compilation errors do not show any source code for crystal eval:

$ cat test.cr
foo
$ crystal test.cr
Showing last frame. Use --error-trace for full trace.

In test.cr:1:1

 1 | foo
     ^--
Error: undefined local variable or method 'foo' for top-level
$ cat test.cr | crystal eval
error in line 1
Error: undefined local variable or method 'foo' for top-level
$ crystal eval "$(cat test.cr)"
Showing last frame. Use --error-trace for full trace.

error in line 1
Error: undefined local variable or method 'foo' for top-level

The source code does have a fictitious filename of eval, and in fact, if a file with that name exists in the current directory, it will be picked up by the compiler:

$ echo abcde > eval
$ cat test.cr | crystal eval
Showing last frame. Use --error-trace for full trace.

In eval:1:1

 1 | abcde
     ^--
Error: undefined local variable or method 'foo' for top-level

[HertzDevil]

It actually also happens for --stdin-filename:

$ cat test.cr | crystal build --stdin-filename x
Showing last frame. Use --error-trace for full trace.

error in line 1
Error: undefined local variable or method 'foo' for top-level
$ cat test.cr | crystal run --stdin-filename x
Showing last frame. Use --error-trace for full trace.

error in line 1
Error: undefined local variable or method 'foo' for top-level