Clerk `:ssr` build fails with `:package :directory`

[formsandlines]

I tried to build Clerk notebooks with :ssr true. It works fine when I also set :package :single-file, but without this option (or :package :directory) I always get this error:

clerk-ssr-test % clojure -X:clerk
👷🏼 Clerk is building 1 notebooks…
🧐 Parsing… Done in 16,737ms. ✅
🔬 Analyzing… Done in 72,402ms. ✅
🔨 Building "notebooks/foo.clj"… Done in 13,158ms. ✅
🧱 Server Side Rendering… Exception in thread "main" java.lang.IllegalArgumentException: Multiple methods in multimethod 'simple-dispatch' match dispatch value: class babashka.process.Process -> interface clojure.lang.IPersistentMap and interface clojure.lang.IDeref, and neither is preferred
        at clojure.lang.MultiFn.findAndCacheBestMethod(MultiFn.java:179)
        at clojure.lang.MultiFn.getMethod(MultiFn.java:150)
        at clojure.lang.MultiFn.getFn(MultiFn.java:154)
        at clojure.lang.MultiFn.invoke(MultiFn.java:229)
        at clojure.pprint$write_out.invokeStatic(pprint_base.clj:194)
        at clojure.pprint$pprint_map$fn__11193$fn__11195.invoke(dispatch.clj:113)
        at clojure.pprint$pprint_map$fn__11193.invoke(dispatch.clj:113)
        at clojure.pprint$pprint_map.invokeStatic(dispatch.clj:112)
        at clojure.pprint$pprint_map.invoke(dispatch.clj:106)
        at clojure.lang.MultiFn.invoke(MultiFn.java:229)
        at clojure.pprint$write_out.invokeStatic(pprint_base.clj:194)
        at clojure.pprint$pprint_vector$fn__11178.invoke(dispatch.clj:95)
        at clojure.pprint$pprint_vector.invokeStatic(dispatch.clj:94)
        at clojure.pprint$pprint_vector.invoke(dispatch.clj:92)
        at clojure.lang.MultiFn.invoke(MultiFn.java:229)
        at clojure.pprint$write_out.invokeStatic(pprint_base.clj:194)
        at clojure.pprint$pprint_map$fn__11193$fn__11195.invoke(dispatch.clj:113)
        at clojure.pprint$pprint_map$fn__11193.invoke(dispatch.clj:113)
        at clojure.pprint$pprint_map.invokeStatic(dispatch.clj:112)
        at clojure.pprint$pprint_map.invoke(dispatch.clj:106)
        at clojure.lang.MultiFn.invoke(MultiFn.java:229)
        at clojure.pprint$write_out.invokeStatic(pprint_base.clj:194)
        at clojure.pprint$pprint_map$fn__11193$fn__11195.invoke(dispatch.clj:113)
        at clojure.pprint$pprint_map$fn__11193.invoke(dispatch.clj:113)
        at clojure.pprint$pprint_map.invokeStatic(dispatch.clj:112)
        at clojure.pprint$pprint_map.invoke(dispatch.clj:106)
        at clojure.lang.MultiFn.invoke(MultiFn.java:229)
        at clojure.pprint$write_out.invokeStatic(pprint_base.clj:194)
        at clojure.pprint$pprint$fn__10434.invoke(pprint_base.clj:249)
        at clojure.pprint$pprint.invokeStatic(pprint_base.clj:248)
        at clojure.pprint$pprint.invoke(pprint_base.clj:241)
        at clojure.pprint$pprint.invokeStatic(pprint_base.clj:245)
        at clojure.pprint$pprint.invoke(pprint_base.clj:241)
        at clojure.lang.Var.invoke(Var.java:386)
        at clojure.main$report_error$fn__9322$fn__9323.invoke(main.clj:604)
        at clojure.main$report_error$fn__9322.invoke(main.clj:603)
        at clojure.main$report_error.invokeStatic(main.clj:602)
        at clojure.main$main.invokeStatic(main.clj:667)
        at clojure.main$main.doInvoke(main.clj:617)
        at clojure.lang.RestFn.applyTo(RestFn.java:140)
        at clojure.lang.Var.applyTo(Var.java:707)
        at clojure.main.main(main.java:40)

I tried the most minimal setup in a test project. The deps.edn looks like this:

{:paths ["notebooks"]
 :deps {org.clojure/clojure {:mvn/version "1.12.1"}
        io.github.nextjournal/clerk {:mvn/version "0.18.1142"}}
 :aliases
 {:clerk
  {:exec-fn nextjournal.clerk/build!
   :exec-args {:paths ["notebooks/foo.clj"]
               :ssr true
               :package :directory
               :out-path "./out"}}}}

notebooks/foo.clj is just:

(ns foo (:require [nextjournal.clerk :as clerk]))

;; # Hello!

I tested it without :ssr true, which works regardless of :package :single-file. The error also happens with Clojure 1.11.1.

Since Babashka is mentioned in babashka.process.Process, I wonder if it has something to do with it? My bb version is 1.12.206, if that matters.

[borkdude]

@formsandlines Unfortunately I can't reproduce this. In the test project you provided I'm getting this output:

The error you are seeing has to do with pprint-ing a babashka process object. I don't know why this is happening though. Perhaps this is happening because there is an error while doing the SSR stuff in node and then the pprint error happens during error handling.

Adding a (:require [babashka.process.pprint]) to your notebook should at least solve that issue. Can you try again and come back with the next error you're seeing, if any?

[formsandlines]

You are right, it might have something to do with node rather than babashka. Trying the build again with your suggestion, I get:

🧱 Server Side Rendering… Execution error (ExceptionInfo) at nextjournal.clerk.builder/ssr! (builder.clj:201).
Clerk ssr! failed

node: bad option: --experimental-network-imports

My node version is v22.13.1 but updating to the newest lts (v22.17.1) returns the same error.

[EDIT]: I see that the option --experimental-network-imports gets passed to node by node-ssr!: https://github.com/nextjournal/clerk/blob/main/src/nextjournal/clerk/builder.clj So maybe it depends on a different node version?

[borkdude]

It seems this was dropped a year ago in v22-something.

nodejs/node#53822

I'm not sure why this flag is necessary. building without the flag works fine in my case locally.

I'll make a PR to drop the flag and ask @mk if he remembers why this was added. But since it's dropped in newer versions of Node.js we'll have to drop it anyway.

[borkdude]

Interestingly I'm seeing the same error as you had initially on CI: https://github.com/nextjournal/clerk/actions/runs/16452386063/job/46500746710?pr=758
I'll just load the babashka.process.pprint namespace in clerk to fix that.

[borkdude]

@formsandlines Should work with this PR: #758

[formsandlines]

Perfect, can confirm that it works! :)