Precompiling executable failing using PUB_CACHE env variable

[pY4x3g]

Environment

• pub version: Pub 2.8.0-20.11.beta
• OS version: Debian 10 (docker image google/dart:latest and google/dart:beta are failing)

Problem

Running tests with a new version of dart is failing when using env variable PUB_CACHE.
The precompiling executable command is running with wrong path to the dart file, see below.

The image is based on google/dart and this problem first occurred after using a newer version of the docker image. The image google/dart:2.6 is running fine.

Expected behavior

Tests should run without error as in google/dart:2.6.

Actual behavior

Precompiling executable failing

--trace output

I used PUB_CACHE=.pub-cache and obtain the error:

pub run -v test
FINE: Pub 2.8.0-20.11.beta
MSG : Precompiling executable...
IO  : Spawning "/usr/lib/dart/bin/dart --packages=file:///***/.packages --snapshot=./.dart_tool/pub/bin/test/test.dart.snapshot.dart2 .pub-cache/hosted/pub.dartlang.org/test-1.14.3/.pub-cache/hosted/pub.dartlang.org/test-1.14.3/bin/test.dart" in ***.
IO  : Finished /usr/lib/dart/bin/dart. Exit code 254.
    | Nothing output on stdout.
    | stderr:
    | | Error: Error when reading '.pub-cache/hosted/pub.dartlang.org/test-1.14.3/.pub-cache/hosted/pub.dartlang.org/test-1.14.3/bin/test.dart': No such file or directory
ERR : Failed to precompile test:test:
    | Error: Error when reading '.pub-cache/hosted/pub.dartlang.org/test-1.14.3/.pub-cache/hosted/pub.dartlang.org/test-1.14.3/bin/test.dart': No such file or directory
FINE: Exception type: ApplicationException
FINE: package:pub/src/dart.dart 64:5              snapshot
    | ===== asynchronous gap ===========================
    | dart:async                                  Future.catchError
    | package:pub/src/utils.dart 149:19           waitAndPrintErrors.<fn>
    | dart:async                                  Future.wait
    | package:pub/src/utils.dart 148:17           waitAndPrintErrors
    | package:pub/src/entrypoint.dart 318:14      Entrypoint.precompileExecutable.<fn>
    | package:pub/src/entrypoint.dart 315:58      Entrypoint.precompileExecutable.<fn>
    | package:pub/src/log.dart 394:18             progress
    | package:pub/src/entrypoint.dart 315:18      Entrypoint.precompileExecutable
    | package:pub/src/command/run.dart 85:25      RunCommand.run.<fn>
    | package:pub/src/executable.dart 131:20      _runOrCompileSnapshot
    | package:pub/src/executable.dart 71:26       runExecutable.<fn>
    | package:pub/src/executable.dart 64:47       runExecutable.<fn>
    | package:pub/src/log.dart 377:32             warningsOnlyUnlessTerminal
    | package:pub/src/executable.dart 64:16       runExecutable
    | package:pub/src/command/run.dart 78:26      RunCommand.run
    | package:args/command_runner.dart 197:27     CommandRunner.runCommand
    | package:pub/src/command_runner.dart 191:39  PubCommandRunner.runCommand.<fn>
    | dart:async                                  new Future.sync
    | package:pub/src/utils.dart 113:12           captureErrors.wrappedCallback
    | package:stack_trace                         Chain.capture
    | package:pub/src/utils.dart 126:11           captureErrors
    | package:pub/src/command_runner.dart 191:13  PubCommandRunner.runCommand
FINE: Precompiling executable finished (0.417s).

The problem lies already inside the

Spawning "/usr/lib/dart/bin/dart --packages=file:///***/.packages --snapshot=./.dart_tool/pub/bin/test/test.dart.snapshot.dart2 .pub-cache/hosted/pub.dartlang.org/test-1.14.3/.pub-cache/hosted/pub.dartlang.org/test-1.14.3/bin/test.dart" in ***.```

part. The path to the dart file seems to be wrong (twice the path?). All was running fine using older versions of dart docker image.

[pY4x3g]

I was able to track down the dart version: Dart version 2.6 and 2.7 are running fine, it seems to start with the 2.8 branch. The error already occurs in google/dart:2.8.0-dev.1.0.

[sigurdm]

This was indeed introduced in #2277 we calculate the path of the executable wrongly, basically doubling it by something that ends up likejoin(a, a). But if it is an absolute path it still works.

Until a fix is out you can work around this with pub get --precompile it doesn't have the same issue.