All API requests fail with Cannot find module 'punycode/'

[carlgieringer]

punycode is included in Node but that built-in version has been deprecated since v7 (but still present in v20) (https://nodejs.org/api/punycode.html#punycode_punycode). People import punycode/ to get the installed version and not the built-in Node version (aws/aws-cdk#11099 (comment)).

I'm not sure why this isn't working suddenly. The issue above mentions esbuild not supporting the punycode/ import. Maybe I added something that depends on this import recently, like jsdom?

esbuild appears intentionally to ignore trailing slashes in imports (https://github.com/evanw/esbuild/blob/2703f90d47fd96f425fedcfd2a5c318a43b04d45/internal/resolver/resolver.go#L374-L384) but also appears to consider punycode an internal module (https://github.com/evanw/esbuild/blob/2703f90d47fd96f425fedcfd2a5c318a43b04d45/internal/resolver/resolver.go#L2564C1-L2564C1). So what I think is happening is that esbuild is leaving imports like require("punycode/") in the built code, but when it comes to run-time, Node considers these external modules, and so fails to resolve them.

Someone solved it by including punycode as a Lambda layer (aws/aws-cdk#14290 (comment)).

(Why didn't our API 'smoke test' catch this?)