Thumbnails not generating

[tkolo]

Dynamic thumbnails do not seem to work for me on latest stable synapse server.
The following error happens on the server:

2017-08-01 23:30:44,477 - synapse.http.server - 139 - ERROR - GET-251446- Failed handle request synapse.rest.media.v1.thumbnail_resource._async_render_GET on <synapse.rest.me
source.ThumbnailResource instance at 0x7f1c89cff488>: <XForwardedForRequest at 0x7f1c8047fa28 method=GET uri=/_matrix/media/v1/thumbnail/kolosowscy.pl/SmBExHmNiwzfKirHWlLuctG
100 clientproto=HTTP/1.0 site=8008>
Traceback (most recent call last):
  File "/srv/synapse/lib/python2.7/site-packages/synapse/http/server.py", line 118, in wrapped_request_handler
    yield request_handler(self, request)
  File "/srv/synapse/lib/python2.7/site-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/srv/synapse/lib/python2.7/site-packages/twisted/python/failure.py", line 393, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "/srv/synapse/lib/python2.7/site-packages/synapse/rest/media/v1/thumbnail_resource.py", line 61, in _async_render_GET
    request, media_id, width, height, method, m_type
  File "/srv/synapse/lib/python2.7/site-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/srv/synapse/lib/python2.7/site-packages/twisted/python/failure.py", line 393, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "/srv/synapse/lib/python2.7/site-packages/synapse/rest/media/v1/thumbnail_resource.py", line 163, in _select_or_generate_local_thumbnail
    media_id, desired_width, desired_height, desired_method, desired_type
  File "/srv/synapse/lib/python2.7/site-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/srv/synapse/lib/python2.7/site-packages/twisted/python/failure.py", line 393, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "/srv/synapse/lib/python2.7/site-packages/synapse/rest/media/v1/media_repository.py", line 294, in generate_local_exact_thumbnail
    input_path, t_path, t_width, t_height, t_method, t_type
  File "/srv/synapse/lib/python2.7/site-packages/twisted/python/threadpool.py", line 250, in inContext
    result = inContext.theWork()
  File "/srv/synapse/lib/python2.7/site-packages/twisted/python/threadpool.py", line 266, in <lambda>
    inContext.theWork = lambda: context.call(ctx, func, *args, **kw)
  File "/srv/synapse/lib/python2.7/site-packages/twisted/python/context.py", line 122, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/srv/synapse/lib/python2.7/site-packages/twisted/python/context.py", line 85, in callWithContext
    return func(*args,**kw)
  File "/srv/synapse/lib/python2.7/site-packages/synapse/rest/media/v1/media_repository.py", line 258, in _generate_thumbnail
    thumbnailer = Thumbnailer(input_path)
  File "/srv/synapse/lib/python2.7/site-packages/synapse/rest/media/v1/thumbnailer.py", line 32, in __init__
    self.image = Image.open(input_path)
  File "/srv/synapse/lib/python2.7/site-packages/PIL/Image.py", line 2477, in open
    fp = builtins.open(filename, "rb")
IOError: [Errno 2] No such file or directory: '/srv/synapse/media_store/local_content/Sm/BE/xHmNiwzfKirHWlLuctGW'

In riot it looks like so:

[jkolo]

Only dynamic thumbnails for url doesn't work

[brainbug89]

Why is the fix for this issue still not pulled to master?!! 🙄

[jkolo]

@brainbug89 PR #2791 fixed this issue :-)