(ns user.my-macro)
(defmacro my-macro1 [a]
  `(locking (Object.)
     (+ ~a 10)))

(ns user.demo-two-clocks
  (:require [hyperfiddle.electric :as e]
            [hyperfiddle.electric-dom2 :as dom]
            #?(:clj [user.my-macro :as mm])))

(e/defn TwoClocks []
  (e/client
    (dom/h1 (dom/text "Two Clocks — Electric Clojure"))
    (let [c (e/client e/system-time-ms)
          s (e/server (mm/my-macro1 100)                                ;; <== Here
                      e/system-time-ms)]
      (dom/div (dom/text "client time: " c))
      (dom/div (dom/text "server time: " s))
      (dom/div (dom/text "latency: " (- s c))))))

[:dev] Compiling ...
DEBUG hyperfiddle.electric.impl.env: reloading user.demo-two-clocks
[:dev] Build failure:
------ ERROR -------------------------------------------------------------------
 File: /Users/philos/src/electric/src-dev/user.cljs:7:20
--------------------------------------------------------------------------------
   4 |             hyperfiddle.rcf
   5 |             user-main))
   6 |
   7 | (def electric-main (hyperfiddle.electric/boot (user-main/Main.)))
--------------------------^-----------------------------------------------------
Encountered error when macroexpanding hyperfiddle.electric/boot.
Unable to resolve symbol: monitor-enter
{:file "user/demo_two_clocks.cljc", :in [monitor-enter]}
ExceptionInfo: Unable to resolve symbol: monitor-enter
	hyperfiddle.electric.impl.compiler/analyze-form (compiler.clj:643) 
...

(defmacro my-macro2 [a]
  `(binding [clojure.core/*print-length* 50]
     (+ ~a 20)))

(ns user.demo-two-clocks
  (:require [hyperfiddle.electric :as e]
            [hyperfiddle.electric-dom2 :as dom]
            #?(:clj [user.my-macro :as mm])))

(e/defn TwoClocks []
  (e/client
    (dom/h1 (dom/text "Two Clocks — Electric Clojure"))
    (let [c (e/client e/system-time-ms)
          s (e/server (mm/my-macro2 100)                                          ;; <== Here
                      e/system-time-ms)]
      (dom/div (dom/text "client time: " c))
      (dom/div (dom/text "server time: " s))
      (dom/div (dom/text "latency: " (- s c))))))

[:dev] Compiling ...
DEBUG hyperfiddle.electric.impl.env: reloading user.demo-two-clocks
[:dev] Build failure:
------ ERROR -------------------------------------------------------------------
 File: /Users/philos/src/electric/src-dev/user.cljs:7:20
--------------------------------------------------------------------------------
   4 |             hyperfiddle.rcf
   5 |             user-main))
   6 |
   7 | (def electric-main (hyperfiddle.electric/boot (user-main/Main.)))
--------------------------^-----------------------------------------------------
Encountered error when macroexpanding hyperfiddle.electric/boot.
Not a reactive var: clojure.core/*print-length*
{:in [(clojure.core/binding [clojure.core/*print-length* 50] (clojure.core/+ 100 20))]}
ExceptionInfo: Not a reactive var: clojure.core/*print-length*
	hyperfiddle.electric.impl.compiler/analyze-form (compiler.clj:643) 
...