Crash on get-gl-context inside gui-lib/mred/private/mrcanvas.rkt

[evilactually]

This minimum OpenGL example causes a crash on Linux, Ubuntu and Gentoo:

#lang racket/base

(require racket/gui
         sgl)

(define (draw-triangle)
  (gl-viewport 0 0 500 500)
  (gl-begin 'triangles)
  (gl-color 1 0 0)
  (gl-vertex 0 0 0)
  (gl-vertex 0.75 0 0)
  (gl-vertex 0.75 0.75 0)
  (gl-end))

(define my-canvas%
  (class* canvas% ()
    (inherit with-gl-context swap-gl-buffers)
    (define/override (on-paint)
      (with-gl-context (lambda () ;; <- CRASH
                         (draw-triangle)
                         (swap-gl-buffers))))
    (super-instantiate () (style '(gl)))))

(define frame (new frame%
                 [label "OpenGL"]
                 [min-width 500]
                 [min-height 500]))

(define canvas (new my-canvas%
                    [parent frame]))

(send frame show #t)

Running directly from DrRacket produces no useful output, but if I compile it and run it I get a stack trace:

invalid memory reference.  Some debugging context lost
 context...:
  .../private/arrow-higher-order.rkt:379:33
  .../private/mrcanvas.rkt:128:4: with-gl-context method in canvas%
  .../Sources/crash.rkt:18:4: on-paint method in my-canvas%
  .../private/more-scheme.rkt:148:2: call-with-break-parameterization
  .../unsafe/atomic.rkt:73:13
  .../common/canvas-mixin.rkt:144:4: do-on-paint method in canvas-mixin
  .../common/queue.rkt:436:6
  .../common/queue.rkt:487:32
  .../common/queue.rkt:639:3
internal error: attempt to deschedule the current thread in atomic mode
 context...:
  .../common/queue.rkt:639:3

I went in and modified mrcanvas.rkt to see where the error is coming from. It crashes when binding the let statement during the call to the get-gl-context method.

(define/public (with-gl-context
                	thunk
                	#:fail [fail (lambda ()
                               	(error (who->name '(method canvas% with-gl-context))
                                      	"no gl context available"))])
  	(displayln "with-gl-context")
  	(displayln (format "(send wx get-dc):~s" (send wx get-dc)))
  	(displayln (format "(send (send wx get-dc) get-gl-context):~s" (send (send wx get-dc) get-gl-context))) ; <- CRASH
;;   	(let ([ctx (send (send wx get-dc) get-gl-context)])
;;     	(if ctx
;;         	(displayln "calling thunk")
;;         	;(send ctx call-as-current thunk)
;;         	(fail)))

  	)

This produces the output:

(send wx get-dc):#(struct:wrapper-object:dc% ...)
invalid memory reference.  Some debugging context lost
 context...:
  .../private/arrow-higher-order.rkt:379:33
  .../private/mrcanvas.rkt:128:4: with-gl-context method in canvas%
  .../Sources/crash.rkt:18:4: on-paint method in my-canvas%
  .../private/more-scheme.rkt:148:2: call-with-break-parameterization
  .../unsafe/atomic.rkt:73:13
  .../common/canvas-mixin.rkt:144:4: do-on-paint method in canvas-mixin
  .../common/queue.rkt:436:6
  .../common/queue.rkt:487:32
  .../common/queue.rkt:639:3
internal error: attempt to deschedule the current thread in atomic mode
 context...:
  .../common/queue.rkt:639:3

Strangely enough, the program does not crash under Ubuntu when I run it as root. I wonder if it's some kind of X or Wayland permission issue, but why would it affect Racket specifically?