The punycode module is deprecated

[Fil]

DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.

[mbostock]

I haven’t seen this. Where did you see this warning, and where is it generated?

[Fil]

Looks like a yarn issue that surfaced with node 21.
yarnpkg/yarn#9005

I don't think we need to do anything, but wait for yarn to get fixed.

I saw it in the build logs of https://huggingface.co/spaces/observablehq/french-newspapers?logs=build

===== Build Queued at 2024-01-29 13:42:58 / Commit SHA: 6d24261 =====

--> FROM docker.io/library/node:latest@sha256:0ded28778059262bd3c066b609186e5b6c89550a9362dce4309ad67c95af0d77
DONE 0.0s

--> RUN arch # print arch info
CACHED

--> RUN useradd -o -u 1000 user
CACHED

--> WORKDIR /home/user/app
CACHED

--> Restoring cache
DONE 6.8s

--> COPY --chown=user . /home/user/app
DONE 0.7s

--> RUN npm install -g serve

added 89 packages in 2s

24 packages are looking for funding
  run `npm fund` for details
npm notice 
npm notice New minor version of npm available! 10.2.4 -> 10.4.0
npm notice Changelog: <https://github.com/npm/cli/releases/tag/v10.4.0>
npm notice Run `npm install -g [email protected]` to update!
npm notice 
DONE 1.8s

--> RUN wget --quiet https://github.com/duckdb/duckdb/releases/download/v0.9.2/duckdb_cli-linux-amd64.zip -O duckdb.zip &&     unzip duckdb.zip && chmod +x duckdb && mv duckdb /usr/local/bin
Archive:  duckdb.zip
  inflating: duckdb                  
DONE 0.7s

--> RUN mkdir -p /tmp/ # note: useless since /tmp already exists
DONE 0.2s

--> RUN yarn && yarn build
yarn install v1.22.19
[1/4] Resolving packages...
[2/4] Fetching packages...
(node:7) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
(Use `node --trace-deprecation ...` to show where the warning was created)
[3/4] Linking dependencies...
warning "@observablehq/cli > [email protected]" has unmet peer dependency "@types/markdown-it@*".
[4/4] Building fresh packages...
Done in 5.61s.
yarn run v1.22.19
$ rm -rf dist && observable build
…

(not a huge issue)

[Fil]

I investigated this a bit more today, since it seems that it is now fixed in yarn 1.22.22: yarnpkg/yarn#9013

I upgraded yarn, but still saw the warning; however running with
❯ NODE_OPTIONS='--trace-deprecation' yarn dev --no-open
showed that the error was now coming from
node_modules/markdown-it/lib/index.js:14:20

fixing it then showed the same issue coming from a transitive dependency psl (jsdom#tough-cookie#psl):
node_modules/psl/index.js:5:16

fixing that, and the warning was gone.

To sum up, three of our dependencies will need an upgrade: yarn, markdown-it, and psl.

The fix in both cases was to transform require("punycode") into require("punycode/"); I haven't tried to understand what it did or why.

[wetlandscapes]

Just an FYI, I get the "punycode" warning when pulling the official node.js docker image (v21, Debian "bookworm"). I tried updating yarn before creating the observable project, but that didn't seem to help.