Error with PyPi toastedmarshmallow 2.15.2.post1

[ChrisDMac]

With the toastedmarshmallow 2.15.2.post1, we are now receiving the following error:

This does not happen with toastedmarshmallow==2.15.2.

Error is:

File "/opt/app-root/lib/python3.6/site-packages/toastedmarshmallow/init.py", line 1, in

  | from marshmallow import SchemaJit
  | ImportError: cannot import name 'SchemaJit'

[ahmetkurukose]

same problem for us also.

[kernelbug]

Probably the order of packages installation might matter. I install dependencies via pip -r mechanism and observe the next thing:
lets suppose requirements.txt contains

...
marshmallow == 3.15.0
marshmallow-enum == 1.5.1
toastedmarshmallow == 2.15.2.post1
...

then it works well.
However the content

...
toastedmarshmallow == 2.15.2.post1
marshmallow-enum == 1.5.1
marshmallow == 3.15.0
...

will lead to aforementioned error for me.
NB pip gives no error.