devmode - Not using JVM instrumentation, but always full restart

Describe the bug

I read from @maxandersen that in 1.11+ devmode new ability to detect wether a change can be applied using JVM instrumentation (what ides uses to update running jvms) or it requires a restart as devmode usually do.

Expected behavior

Hot swap/reload applying JVM instrumentation, without a restart.

Actual behavior

There´s always a restart, see logs below:

12:38:28: Executing task 'quarkusDev'...


> Task :quarkusGenerateCode
preparing quarkus application

> Task :compileJava
> Task :processResources UP-TO-DATE
> Task :classes

> Task :quarkusDev
Listening for transport dt_socket at address: 5005

2021-03-22 12:38:35,557 INFO  [io.quarkus] (Quarkus Main Thread) my-artifactId my-version on JVM (powered by Quarkus 1.12.2.Final) started in 3.008s. Listening on: http://localhost:8080
2021-03-22 12:38:35,561 INFO  [io.quarkus] (Quarkus Main Thread) Profile dev activated. Live Coding activated.
2021-03-22 12:38:35,562 INFO  [io.quarkus] (Quarkus Main Thread) Installed features: [cdi, resteasy, resteasy-jackson]
2021-03-22 12:38:51,100 INFO  [io.qua.dep.dev.RuntimeUpdatesProcessor] (vert.x-worker-thread-1) Changed source files detected, recompiling [/Users/admin/dev/others/my-artifactId/src/main/java/org/my/group/MyResource.java]
2021-03-22 12:38:51,597 WARN  [io.qua.dep.dev.JavaCompilationProvider] (vert.x-worker-thread-1) system modules path not set in conjunction with -source 11, line -1 in [unknown source]
2021-03-22 12:38:51,663 INFO  [io.quarkus] (Quarkus Main Thread) my-artifactId stopped in 0.065s

2021-03-22 12:38:52,370 INFO  [io.quarkus] (Quarkus Main Thread) my-artifactId my-version on JVM (powered by Quarkus 1.12.2.Final) started in 0.701s. Listening on: http://localhost:8080
2021-03-22 12:38:52,371 INFO  [io.quarkus] (Quarkus Main Thread) Profile dev activated. Live Coding activated.
2021-03-22 12:38:52,371 INFO  [io.quarkus] (Quarkus Main Thread) Installed features: [cdi, resteasy, resteasy-jackson]
2021-03-22 12:38:52,371 INFO  [io.qua.dep.dev.RuntimeUpdatesProcessor] (vert.x-worker-thread-1) Hot replace total time: 1.273s 

To Reproduce

• I´ve used directly the output of

 mvn io.quarkus:quarkus-maven-plugin:1.12.2.Final:create \
    -DprojectGroupId=my-groupId \
    -DprojectArtifactId=my-artifactId \
    -DprojectVersion=my-version \
    -DclassName="org.my.group.MyResource" \
    -Dextensions="resteasy,resteasy-jackson" \
    -DbuildTool=gradle

Environment (please complete the following information):

Intellij IDEA community 2020.3 build 203.5981.155 (also from console directly) OS: Mac Quarkus 1.12.2

Output of java -version

java -version openjdk version “15” 2020-09-15 OpenJDK Runtime Environment (build 15+36-1562) OpenJDK 64-Bit Server VM (build 15+36-1562, mixed mode, sharing)

GraalVM version (if different from Java)

Not used

Quarkus version or git rev

1.12.2

Build tool (ie. output of mvnw --version or gradlew --version)

Gradle 6.8.3

[glefloch]

Good catch, I’m taking care of it.

[geoand]

It seems that the javaagent jvm arg is not set by default for gradle, unlike for maven: https://github.com/quarkusio/quarkus/blob/main/devtools/maven/src/main/java/io/quarkus/maven/DevMojo.java#L826. I was able to make the intrumentation work via:

quarkusDev {
    jvmArgs = ['-javaagent:/path/to/quarkus-class-change-agent-999-SNAPSHOT.jar']
}

Which of course not very user friendly 😉.

Yeah, we definitely need to make this work OOTB for Gradle