#+title: Clojure bugs
I bisected this to [[https://git.savannah.gnu.org/cgit/emacs/org-mode.git/commit/?id=6efb073463481ee572eb3bb1155cc3b0d6987df6][6efb073463481ee572eb3bb1155cc3b0d6987df6]]. I've only
tested this on =cider=, I'm not sure if that makes a difference.

* Preface
I'm running this via =make repro=, on [[https://git.savannah.gnu.org/cgit/emacs/org-mode.git/commit/?id=405787dfbcbd4ae5e1d2227ce5aa7d4d20938388][405787dfbcbd4ae5e1d2227ce5aa7d4d20938388]].

This installs and loads =cider= and =clojure-mode= - I usually do this
via =use-package= but that makes the config for this a bit more
complicated, so please forgive any uncommon practices.

#+begin_src elisp :results silent
  (require 'ob-core)
  ;(setq org-confirm-babel-evaluate nil)
  (org-babel-do-load-languages 'org-babel-load-languages
  			     '((shell . t)
  			       (clojure . t)))

  (require 'ob-clojure)
  (setq org-babel-clojure-backend 'cider)

  (require 'package)
  (package-initialize)

  (package-refresh-contents)
  (package-install 'clojure-mode)
  (package-install 'cider)

  (add-to-list 'load-path "~/.emacs.d")

  (require 'clojure-mode)
  (require 'cider)
#+end_src

* Bug 1: Different namespaces in the same document don't work well
Say I have the following structure:

** Util
:PROPERTIES:
:header-args:clojure: :exports both :session *clojure-util*
:END:

It seems ~(ns example.util)~ isn't run properly in the first code
block: =sum= gets added to the default =user= namespace the first time
it's run. The second time it's run, it does work as expected. In
general, a block with a ~(ns)~ call needs to be run twice, it
seems?

Rather than executing the code blocks below, check the list of CALLS
below them so they're executed in the correct order.

#+name: define-sum
#+begin_src clojure
  (ns example.util)
  (defn sum [vec]
    (reduce + vec))
#+end_src

#+name: use-sum
#+begin_src clojure
  (sum (range 10))
#+end_src

*** Calls
Execute these calls one by one:

For this one, I use =cider-jack-in-clj=.
#+CALL: define-sum()

#+RESULTS:
: Please reevaluate when nREPL is connected

The call below should, imo, add =sum= to the =util= namespace, which
it doesn't.
#+CALL: define-sum()

#+RESULTS:
: #'user/sum

Therefore, the call below errors:
#+CALL: use-sum()

#+RESULTS:
: class clojure.lang.Compiler$CompilerException

When =define-sum= is run for the second time, it's added correctly.
#+CALL: define-sum()

#+RESULTS:
: #'example.util/sum

And it can be used as expected.
#+CALL: use-sum()

#+RESULTS:
: 45

** Program using Util
:PROPERTIES:
:header-args:clojure: :exports both :session *clojure-01*
:END:

This code block always errors:
#+begin_src clojure
  (ns example.program
    (:require [example.util :as util]))

  (util/sum (range 10))
#+end_src

#+RESULTS:
: class clojure.lang.Compiler$CompilerException

* Bug 2: When tangling, code blocks can't see previously defined vars
:PROPERTIES:
:header-args:clojure: :tangle tangled.clj :session *clojure-tangle* :results none
:END:

Let's create a clojure file that first defines a function =sum=:
#+begin_src clojure
  (ns example.tangle)

  (defn sum [xs] (reduce + xs))
#+end_src

And then uses it:
#+begin_src clojure
  (sum (range 10))
#+end_src

If we tangle this subtree, we get the following output:
#+begin_src elisp
  (org-babel-tangle)
  (with-temp-buffer
    (insert-file-contents "tangled.clj")
    (buffer-string))
#+end_src

#+RESULTS:
: (prn (binding [*out* (java.io.StringWriter.)](ns example.tangle)
: 
: (defn sum [xs] (reduce + xs))))
: 
: (prn (binding [*out* (java.io.StringWriter.)](sum (range 10))))

Note that each code block is wrapped in an invidiual =(prn (binding
...))= block. This means that later code blocks have a different scope
to prior code blocks. Executing this file also leads to an error:

#+begin_src sh :results output
  clj -M tangled.clj 2>&1
#+end_src

#+RESULTS:
: #'user/sum
: Syntax error compiling at (tangled.clj:5:46).
: Unable to resolve symbol: sum in this context
: 
: Full report at:
: /tmp/clojure-11215251630972501185.edn