This happens with 1.10.339 and also with current master:
$ clj -m cljs.main -co '{:checked-arrays :warn}' -r
ClojureScript 1.10.424
cljs.user=> (aget #js {:foo 1} "foo")
WARNING: cljs.core/aget, arguments must be an array followed by numeric indices, got [object string] instead (consider goog.object/get for object access) at line 1 <cljs repl>
Exception in thread "Thread-128" java.lang.RuntimeException: Agent is failed, needs restart
at clojure.lang.Util.runtimeException(Util.java:225)
at clojure.lang.Agent.dispatch(Agent.java:238)
at clojure.core$send_via.invokeStatic(core.clj:2101)
at clojure.core$send_via.doInvoke(core.clj:2093)
at clojure.lang.RestFn.invoke(RestFn.java:494)
at cljs.repl.browser$constrain_order.invokeStatic(browser.clj:255)
at cljs.repl.browser$constrain_order.invoke(browser.clj:251)
at cljs.repl.browser$fn__7428.invokeStatic(browser.clj:267)
at cljs.repl.browser$fn__7428.invoke(browser.clj:266)
at clojure.lang.MultiFn.invoke(MultiFn.java:238)
at cljs.repl.server$dispatch_request.invokeStatic(server.clj:190)
at cljs.repl.server$dispatch_request.invoke(server.clj:182)
at cljs.repl.server$handle_connection.invokeStatic(server.clj:199)
at cljs.repl.server$handle_connection.invoke(server.clj:195)
at cljs.repl.server$server_loop$fn__6162.invoke(server.clj:209)
at clojure.core$binding_conveyor_fn$fn__5476.invoke(core.clj:2022)
at clojure.lang.AFn.run(AFn.java:22)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.RuntimeException: Invalid token: Error:
at clojure.lang.Util.runtimeException(Util.java:221)
at clojure.lang.LispReader.interpretToken(LispReader.java:402)
at clojure.lang.LispReader.read(LispReader.java:295)
at clojure.lang.LispReader.readDelimitedList(LispReader.java:1384)
at clojure.lang.LispReader$VectorReader.invoke(LispReader.java:1333)
at clojure.lang.LispReader.read(LispReader.java:275)
at clojure.lang.LispReader.read(LispReader.java:210)
at clojure.lang.LispReader.access$200(LispReader.java:41)
at clojure.lang.LispReader$CtorReader.invoke(LispReader.java:1408)
at clojure.lang.LispReader$DispatchReader.invoke(LispReader.java:836)
at clojure.lang.LispReader.read(LispReader.java:275)
at clojure.lang.LispReader.read(LispReader.java:206)
at clojure.lang.LispReader.read(LispReader.java:195)
at clojure.lang.RT.readString(RT.java:1871)
at clojure.lang.RT.readString(RT.java:1866)
at clojure.core$read_string.invokeStatic(core.clj:3781)
at clojure.core$read_string.invoke(core.clj:3771)
at cljs.repl.browser$fn__7420$fn__7422.invoke(browser.clj:262)
at cljs.repl.browser$run_in_order.invokeStatic(browser.clj:247)
at cljs.repl.browser$run_in_order.invoke(browser.clj:243)
at clojure.core$binding_conveyor_fn$fn__5476.invoke(core.clj:2025)
at clojure.lang.AFn.applyToHelper(AFn.java:154)
at clojure.lang.RestFn.applyTo(RestFn.java:132)
at clojure.lang.Agent$Action.doRun(Agent.java:114)
at clojure.lang.Agent$Action.run(Agent.java:163)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
... 1 more
