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pantsbuild / pants

The Pants Build System
https://www.pantsbuild.org
Apache License 2.0
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Intermittent artificial dependency cycles #18992

Open fabric-gh opened 1 year ago

fabric-gh commented 1 year ago

Often when editing/saving files or switching branches and then running a command, pants reports an error:

IntrinsicError: The dependency graph contained a cycle:
  @rule(pants.core.util_rules.source_files.determine_source_files()) <-
@rule(pants.engine.internals.graph.hydrate_sources(third_party/glog:glog))
@rule(pants.backend.shell.util_rules.shell_command.shell_command_in_sandbox())
@rule(pants.backend.shell.util_rules.shell_command.run_adhoc_result_from_target())
@rule(pants.core.util_rules.source_files.determine_source_files()) <-

This isn't a real dependency cycle, it goes away if we pkill pantsd and run again. In this particular case above, third_party/glog:glog is a target in our repo, but I wasn't changing anything in that directory at the time. This seems to happen more if we run a command quickly after saving a file (i.e. if we wait a few seconds, it happens less).

Context: We use experimental_shell_command rules that wrap scripts to build C++, putting .o files into e.g. /dist/build, then later linking a binary by find'ing everything in dist/build.

benjyw commented 1 year ago

@fabric-gh is this still an issue? If so, can you provide a small repo that reliably reproduces it under some conditions? It will be hard to fix without a repro. Thanks!