Allow fallback from runfiles lookup in edge cases #27
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Currently, libjvm_stub exits if the C++ runfiles library detects runfiles but then fails to find the JDK. This was based on the assumption that this situation could only occur if e.g. Bazel rules would improperly forward runfiles. However, this can also happen when the binary using libjvm_stub is itself launched from another, top-level binary that does not set the variables used for runfiles discovery. If the top-level binary uses a runfiles manifest to find the current binary, it will execute it using a path that points into the Bazel cache directory. Since the contents of the cache are not hermetic, an adjacent out-of-date .runfiles directory or MANIFEST may exist as a left-over from a previous direct run of the current binary. Since there is no way to detect this scenario, fall back to a system-provided JDK but print a warning. Also print all Bazel-related warnings to stderr rather than stdout.
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@simonresch FYI |
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Currently, libjvm_stub exits if the C++ runfiles library detects
runfiles but then fails to find the JDK. This was based on the
assumption that this situation could only occur if e.g. Bazel rules
would improperly forward runfiles.
However, this can also happen when the binary using libjvm_stub is itself
launched from another, top-level binary that does not set the variables
used for runfiles discovery. If the top-level binary uses a runfiles
manifest to find the current binary, it will execute it using a path
that points into the Bazel cache directory. Since the contents of the
cache are not hermetic, an adjacent out-of-date .runfiles directory or
MANIFEST may exist as a left-over from a previous direct run of the
current binary. Since there is no way to detect this scenario, fall back
to a system-provided JDK but print a warning.
Also print all Bazel-related warnings to stderr rather than stdout.