Add debugging tips to the dev docs

1 files changed, 13 insertions, 2 deletions

diff --git a/DEVELOPER_GUIDE.txt b/DEVELOPER_GUIDE.txt
index e42277e..a26d760 100644
--- a/DEVELOPER_GUIDE.txt
+++ b/DEVELOPER_GUIDE.txt
@@ -1,17 +1,28 @@
 Welcome developer.
 
-CBT has a very easy code base that you can fully master in very little time.
+CBT has a very easy code base that's easy to master.
 Don't shy away from submiting PRs :). And because CBT bootstraps from source
 you already have the code there.
 
+The only tricky parts are class loading and cache invalidation. Most changes
+will not need to interfere with this though.
+
 The ./cbt bash script starts the process.
 
 You currently need javac, nailgun, gpg and realpath or gcc installed.
 
+If you have any troubles with class not found, method not found,
+abstract method error, NullPointerException, etc.
+Try `killall -KILL java`. To restart nailgun.
+Or try `cbt direct <taskname>` to circumvent nailgun.
+It can also help to delete all target folders `find .|grep target\$|xargs rm -rf`
+inside of CBT. Or (almost never) the `cache/` directory.
+
 CBT's directory structure
 
 cbt                 Shell script launching cbt. Can be symlinked.
-bootstrap_scala/    Self-contained downloader for the core Scala jars. Allows bootstrapping from Java into Scala.
+compatibility/      Java interfaces that all CBT versions are source compatible to. For communication
+                    between composed builds of different versions.
 nailgun_launcher/   Self-contained helper that allows using Nailgun with minimal permanent classpath. (Is this actually needed?)
 realpath/           Self-contained realpath source code to correctly figure our CBTs home directory. (Open for replacement ideas.)
 stage1/	            CBT's code that only relies only on Scala/Java built-ins. Contains a Maven resolver to download libs for stage2.