Dependency issue: "ImportError: cannot import name 'soft_unicode' from 'markupsafe'"

[rossmotley]

I installed amaranth for the first time (version 0.3), and encountered this error:

ImportError: cannot import name 'soft_unicode' from 'markupsafe'

I found the same error which says that it's due to a change in version 2.1.0 of markupsafe.

I fixed it locally by changing to an older version with pip install markupsafe==2.0.1.

Stack trace:

...snip...
  File "/Users/rossmotley/Library/Python/3.8/lib/python/site-packages/amaranth/build/__init__.py", line 3, in <module>
    from .plat import *
  File "/Users/rossmotley/Library/Python/3.8/lib/python/site-packages/amaranth/build/plat.py", line 6, in <module>
    import jinja2
  File "/Users/rossmotley/Library/Python/3.8/lib/python/site-packages/jinja2/__init__.py", line 12, in <module>
    from .environment import Environment
  File "/Users/rossmotley/Library/Python/3.8/lib/python/site-packages/jinja2/environment.py", line 25, in <module>
    from .defaults import BLOCK_END_STRING
  File "/Users/rossmotley/Library/Python/3.8/lib/python/site-packages/jinja2/defaults.py", line 3, in <module>
    from .filters import FILTERS as DEFAULT_FILTERS  # noqa: F401
  File "/Users/rossmotley/Library/Python/3.8/lib/python/site-packages/jinja2/filters.py", line 13, in <module>
    from markupsafe import soft_unicode
ImportError: cannot import name 'soft_unicode' from 'markupsafe' (/Users/rossmotley/Library/Python/3.8/lib/python/site-packages/markupsafe/__init__.py)

[Lunaphied]

Yes, I’ve encountered this recently too. Are you installing Amaranth with pip or with poetry?

[dragonmux]

@lethalbit hit this issue yesterday and it turned out to be caused by using an out of date Jinja2 - if you're using Jinja2 versions less than 3 then you'll hit this.

[Lunaphied]

The issue is that if you upgrade to Jinja2 3.1.0 or higher this will break Amaranth itself as the API changes made in that version rename features used in amaranth.build

[rossmotley]

@modwizcode I installed via pip, and @dragonmux I got Jinja2 at version 2.11.3.

[dragonmux]

You want Jinja2 version 3.0.3 - this will work correctly and without error

[Lunaphied]

The correct fix is likely to fix the use of deprecated structures in Amaranth and upgrade the constraint on Jinja2 if possible. Otherwise Amaranth will have to fix a dependency on a specific version of markupsafe to avoid letting the constraint be filled with a newer incompatible version.

You hit this issue immediately with poetry because (mostly a guess) it’s constraint solver seems to try to solve for latest versions and pip seems to go for the earliest allowed versions.