* when mvn does a local 'install', it doesn't update the pom.xml last modified time if the pom.xml content hasn't changed
* an ivy.xml includes publicationDate, so an ivy.xml will always be touched even if the other content hasn't changed
* when Ivy checks if a snapshot is uptodate
+ it sees a SNAPSHOT, so it knows the module metadata and artifacts might change
+ it then checks the lastModified time of the metadata
+ if unchanged, it uses the cached information
+ if useOrigin is effectively false (either it is explicitly false or a resource is remote/isLocal=false),
this means that a new artifact won't be retrieved
* the Ivy IBiblioResolver
+ must be used for Maven repositories for proper behavior (no FileResolver, for example)
+ only returns URLResources, even for file: URLs
+ a FileResource is needed in combination with useOrigin to avoid copying artifacts from .m2/repository/
This commit fixes the above by setting a custom URLRepository on a constructed IBiblioResolver.
This URLRepository returns FileResources for file: URLs and standard URLResources for others.
The returned FileResource has isLocal=true and sbt sets useOrigin=true by default, so the artifacts
are used from the origin.
If it turns out a similar situation happens when mvn publishes to remote repositories, it is likely the fix for
that would be to figure out how to disable the lastModified check on the metadata and always download the metadata.
This would be slower, however.
The startup script should set sbt.cygwin=true if running from cygwin.
This will set the terminal type properly for JLine if not already set.
If sbt.cygwin=false or unset and os.name includes "windows", JAnsi is
downloaded by the launcher and installed on standard out/err.
The value for jline.terminal is transformed from explicit jline.X to
the basic types "windows", "unix", or "none". Now that sbt uses JLine
2.0, these types are understood by both sbt's JLine and Scala's.
Older Scala versions shaded the classes but not the terminal property
so both couldn't be configured with a class name at the same time.
Set sbt.task.timings=true to print timings for tasks.
This sample progress handler shows how to get names for tasks and
deal with flatMapped tasks. There are still some tasks that make
it through as anonymous, which needs to be investigated.
A setting to provide a custom handler should come in a subsequent commit.
Construction of Scala providers was already properly synchronized jvm and machine-wide.
The cache on top of construction was not and neither was the newer ClassLoaderCache.
This could cause the same Scala version to be loaded in multiple class loaders, taking
up more permgen space and possibly decreasing performance due to less effective jit.
The issue is very rare in practice for 0.13 because of the low probability of contention
on ClassLoaderCache. This is because the work for a cache miss is mainly the construction
of a URLClassLoader. In 0.12, however, the work potentially involved network access and
class loading (not just class loader construction), thus greatly increasing the probability
of contention and thus duplicate work (i.e. class loader construction).
When there is contention, multiple class loaders are constructed and then preserved by the
scalaInstance task in each project throughout the first task execution. Only when multiple
scalaInstance tasks execute simultaneously and only during the first execution does this occur.
(Technically, it could still happen later, but it doesn't in practice.)
This means that the number of duplicate class loaders should quickly saturate instead of growing
linearly with the number of projects. It also means that the impact depends on the exact
tree structure of projects. A linear chain of dependencies will be unaffected, but a build with
independent leaves may be limited by the number of cores. The number of cores affects
the number of threads typically used by the task engine, which limits the number of concurrently
executing scalaInstance tasks.
In summary, this might affect the first, cold compilation of a multi-module project with
independent leaves on a multi-core machine with Scala version different from the version used
for sbt. It might increase the maximum permgen requirements as well as slow the jit compilation
by up to one task execution. Subsequent compilations should be unaffected and the permgen
utilization return to be as expected.
Support a definitive flag for Failure that ignores later failures
instead of appending them. This is useful to override the default
behavior of listing the failures of alternative parsers.
Mark Harrah
James Roper