Nested relative include?

[WeeknightMVP]

Are relative include paths meant to work within another include?

// test/A/B/C.cry
module A::B::C where
import A::B::D::E::F
include "G/H.pcry"  // succeeds when run from `test/`

// test/A/B/D/E/F.cry
module A::B::D::E::F where
x = 1

// test/A/B/G/H.pcry
y = 2
include "I.pcry"  # fails unless absolute path; no path relative to any parent is found

// test/A/B/G/I.pcry
z = 3

test$ cryptol
...
Cryptol> :m A::B::C  // include "I.pcry"
Loading module Cryptol
Loading module A::B::D::E::F
Loading module A::B::C

`I.pcry` included at G/H.pcry:2:9--2:17 was not found
Cryptol> :m A::B::C  // include "G/I.pcry"
Loading module Cryptol
Loading module A::B::D::E::F
Loading module A::B::C

`G/I.pcry` included at G/H.pcry:2:9--2:19 was not found
Cryptol> :m A::B::C  // include "B/G/I.pcry"
Loading module Cryptol
Loading module A::B::D::E::F
Loading module A::B::C

`B/G/I.pcry` included at G/H.pcry:2:9--2:21 was not found
Cryptol> :m A::B::C  // include "A/B/G/I.pcry"
Loading module Cryptol
Loading module A::B::D::E::F
Loading module A::B::C

`A/B/G/I.pcry` included at G/H.pcry:2:9--2:23 was not found
Cryptol> :m A::B::C  // include "test/A/B/G/I.pcry"
Loading module Cryptol
Loading module A::B::D::E::F
Loading module A::B::C

`test/A/B/G/I.pcry` included at G/H.pcry:2:9--2:28 was not found
Cryptol> :m A::B::C  // include "/.../test/A/B/G/I.pcry"
Loading module Cryptol
Loading module A::B::D::E::F
Loading module A::B::C
A::B::C> 

[yav]

Hello, it's been long enough that I don't remember the thinking behind include, but looking at the source code I'd say this is a bug, as the code already is trying to handle includes relative to other includes. Fortunately, this looks like a simple 1line fix, that I did locally and things seem to work as expected. To help me see what's happening, I also modified the error message to show the path relative to which it was looking for things, which might be a good thing to commit anyway, as it seems like a helpful piece of information.

I'll make a PR later today.