=>> cat target/shadow-cljs/logging.properties

error.log

=>> yarn watch
yarn run v1.3.2
$ shadow-cljs watch browser
shadow-cljs - config: /Users/chen/repo/mvc-works/calcit-workflow/shadow-cljs.edn version: 2.1.6
shadow-cljs - starting ...
Can't load log handler "java.util.logging.FileHandler"
java.nio.file.NoSuchFileException: /Users/chen/repo/mvc-works/coworkflow/target/shadow-cljs/shadow-cljs.log.0.lck
java.nio.file.NoSuchFileException: /Users/chen/repo/mvc-works/coworkflow/target/shadow-cljs/shadow-cljs.log.0.lck
	at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
	at sun.nio.fs.UnixFileSystemProvider.newFileChannel(UnixFileSystemProvider.java:177)
	at java.nio.channels.FileChannel.open(FileChannel.java:287)
	at java.nio.channels.FileChannel.open(FileChannel.java:335)
	at java.util.logging.FileHandler.openFiles(FileHandler.java:459)
	at java.util.logging.FileHandler.<init>(FileHandler.java:263)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at java.lang.Class.newInstance(Class.java:442)
	at java.util.logging.LogManager$5.run(LogManager.java:966)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.util.logging.LogManager.loadLoggerHandlers(LogManager.java:958)
	at java.util.logging.LogManager.initializeGlobalHandlers(LogManager.java:1578)
	at java.util.logging.LogManager.access$1500(LogManager.java:145)
	at java.util.logging.LogManager$RootLogger.accessCheckedHandlers(LogManager.java:1667)
	at java.util.logging.Logger.getHandlers(Logger.java:1777)
	at java.util.logging.Logger.log(Logger.java:735)
	at org.jboss.logging.JDKLogger.doLogf(JDKLogger.java:64)
	at org.jboss.logging.Logger.logf(Logger.java:2398)
	at org.xnio._private.Messages_$logger.greeting(Messages_$logger.java:115)
	at org.xnio.Xnio.<clinit>(Xnio.java:104)
	at io.undertow.Undertow.start(Undertow.java:116)
	at shadow.undertow$start.invokeStatic(undertow.clj:155)
	at shadow.undertow$start.invoke(undertow.clj:123)
	at shadow.cljs.devtools.server$start_http$fn__25821.invoke(server.clj:116)
	at shadow.cljs.devtools.server$start_http.invokeStatic(server.clj:115)
	at shadow.cljs.devtools.server$start_http.invoke(server.clj:111)
	at shadow.cljs.devtools.server$start_system.invokeStatic(server.clj:151)
	at shadow.cljs.devtools.server$start_system.invoke(server.clj:132)
	at shadow.cljs.devtools.server$start_BANG_.invokeStatic(server.clj:222)
	at shadow.cljs.devtools.server$start_BANG_.invoke(server.clj:212)
	at shadow.cljs.devtools.server$start_BANG_.invokeStatic(server.clj:215)
	at shadow.cljs.devtools.server$start_BANG_.invoke(server.clj:212)
	at shadow.cljs.devtools.server$from_cli.invokeStatic(server.clj:331)
	at shadow.cljs.devtools.server$from_cli.invoke(server.clj:307)
	at shadow.cljs.devtools.cli$blocking_action.invokeStatic(cli.clj:124)
	at shadow.cljs.devtools.cli$blocking_action.invoke(cli.clj:111)
	at shadow.cljs.devtools.cli$main.invokeStatic(cli.clj:172)
	at shadow.cljs.devtools.cli$main.doInvoke(cli.clj:127)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.core$apply.invokeStatic(core.clj:661)
	at clojure.core$apply.invoke(core.clj:652)
	at shadow.cljs.devtools.cli$_main.invokeStatic(cli.clj:214)
	at shadow.cljs.devtools.cli$_main.doInvoke(cli.clj:212)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.lang.Var.applyTo(Var.java:702)
	at clojure.core$apply.invokeStatic(core.clj:657)
	at clojure.main$main_opt.invokeStatic(main.clj:317)
	at clojure.main$main_opt.invoke(main.clj:313)
	at clojure.main$main.invokeStatic(main.clj:424)
	at clojure.main$main.doInvoke(main.clj:387)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.lang.Var.applyTo(Var.java:702)
	at clojure.main.main(main.java:37)
shadow-cljs - HTTP server for ":browser" available at http://localhost:7000
shadow-cljs - server running at http://0.0.0.0:9630
shadow-cljs - socket repl running at localhost:5900
shadow-cljs - watching build :browser
[:browser] Configuring build.
[:browser] Compiling ...
[:browser] Build completed. (195 files, 1 compiled, 0 warnings, 3.55s)

logging.properties

handlers=java.util.logging.FileHandler, java.util.logging.ConsoleHandler

.level=INFO

java.util.logging.FileHandler.limit=5000000
java.util.logging.FileHandler.count=3
java.util.logging.FileHandler.append=true
java.util.logging.FileHandler.formatter=java.util.logging.SimpleFormatter
java.util.logging.FileHandler.level=INFO

java.util.logging.ConsoleHandler.formatter=java.util.logging.SimpleFormatter
java.util.logging.ConsoleHandler.level=WARNING

java.util.logging.SimpleFormatter.format=[%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS - %4$s] %5$s%6$s%n


java.util.logging.FileHandler.pattern=/Users/chen/repo/mvc-works/coworkflow/target/shadow-cljs/shadow-cljs.log

Hi @chenyong I've caught the same error:

Can't load log handler "java.util.logging.FileHandler"

did you figure out the solution?