Setup on Intel Mac not working

[Jeremy Herbert]

Hi,

I am trying to use YoWASP with nmigen on an Intel Mac (on Catalina), but it seems that it is not detected by nmigen. pip freeze inside my virtualenv looks like this:

appdirs==1.4.4
bitarray==2.3.4
click==8.0.2
Jinja2==3.0.2
MarkupSafe==2.0.1
nmigen==0.2
nmigen-boards==0.0
nmigen-soc==0.0
nmigen-stdio==0.0
nmigen-tool==0.0.1
nmigen-yosys==0.9.post3746.dev34
pyvcd==0.1.7
six==1.16.0
wasmtime==0.30.0
yowasp-nextpnr-ecp5==0.0.post3849.dev224
yowasp-nextpnr-ecp5-all==0.0.post3849.dev224
yowasp-nextpnr-ice40==0.0.post3849.dev224
yowasp-nextpnr-ice40-all==0.0.post3849.dev224
yowasp-yosys==0.9.post5623.dev231

When I try to run the 01_blinky.py example, I get the following traceback:

Traceback (most recent call last):
  File "/Users/jeremy/Seafile/misc_projects/nmigen_playing/main.py", line 21, in <module>
    platform.build(Blinky(), do_program=False)
  File "/Users/jeremy/Seafile/misc_projects/nmigen_playing/venv/lib/python3.9/site-packages/nmigen/build/plat.py", line 71, in build
    require_tool(tool)
  File "/Users/jeremy/Seafile/misc_projects/nmigen_playing/venv/lib/python3.9/site-packages/nmigen/_toolchain.py", line 33, in require_tool
    raise ToolNotFound("Could not find required tool {} in PATH. Place "
nmigen._toolchain.ToolNotFound: Could not find required tool yosys in PATH. Place it directly in PATH or specify path explicitly via the YOSYS environment variable

yowasp-yosys and yowasp-nextpnr-* are definitely on my path; yowasp-yosys --version returns:

Yosys 0.10+12 (git sha1 356ec7bb, ccache clang 11.0.0-2~ubuntu20.04.1 -Os -flto -flto)

Do I need to specifically force the use of YoWASP using the environment variables mentioned in the traceback?

[Catherine]

There's a subtlety here that I think tripped you up: the nmigen-yosys package (which is being used properly) is only useful to generate Verilog. You're building an example that uses a board, which needs a complete toolchain. There is no special knowledge of YoWASP in nMigen; so you're expected to provide the environment variables, just like if you were using any other toolchain build that doesn't put Yosys on PATH.

[Jeremy Herbert]

Thank you! That makes sense.

Perhaps this is an issue for a different tracker, but I do have the YoWASP toolchain on my path (incl all of the ice40/ecp5 tools), but nmigen doesn't seem to be detecting it. Is it because of the yowasp- prefix on all of the commands?

[Catherine]

Yes. The prefix is added to avoid collisions between native binaries on PATH (if any) and PyPI binaries.

[Jeremy Herbert]

ok great, thank you.