"failed to discover package requirements" when using PULUMI_RUN_PROGRAM=true

What happened?

I have recreated my problem here: Se https://github.com/anderius/pulumi-run-program/blob/main/src/main/kotlin/org/example/App.kt#L30

I am new to Pulumi, and I am using it to configure resources in GitHub (and other places). My users can configure stuff in a user interface, and I save the configuration in a database. Then I use Pulumi to apply that configuration to the cloud infrastructure.

To support changing the credentials used, I have understood that I have to use PULUMI_RUN_PROGRAM=true (see https://github.com/pulumi/pulumi/issues/4981). This fails, see the attached example.

Example

Se here: https://github.com/anderius/pulumi-run-program

In short, this is how I run the program:

val program = PulumiProgram()

            LocalWorkspace.createOrSelectStack(
                "inline_project_java", "my_stack", program::program,
                LocalWorkspaceOptions.builder()
                    .environmentVariables(
                        mapOf(
                            "PULUMI_BACKEND_URL" to "file:./pulumi_backend",
                            "PULUMI_CONFIG_PASSPHRASE" to "we-don't-care-about-encryption-here",
                            // Change this to "true" to re-create the error:
                            "PULUMI_RUN_PROGRAM" to "false",
                        ),
                    )
                    .build(),
            ).use { stack ->
                stack.refresh(
                    RefreshOptions.builder()
                        .onStandardOutput(::println)
                        .onStandardError(::println)
                        .build(),
                )
            }

This works:

Refreshing (my_stack):

Resources:

Duration: 1s

Changing PULUMI_RUN_PROGRAM to "true" (needed when I run with credentials), it fails with the following error:

Refreshing (my_stack):
error: failed to discover package requirements: language host could not determine Pulumi packages: could not find ./sbt, sbt on the $PATH: exec: "sbt": executable file not found in $PATH
2 actionable tasks: 1 executed, 1 from cache
Exception in thread "main" com.pulumi.automation.CommandException: code: 255
stdout: Refreshing (my_stack):

stderr: error: failed to discover package requirements: language host could not determine Pulumi packages: could not find ./sbt, sbt on the $PATH: exec: "sbt": executable file not found in $PATH


	at com.pulumi.automation.LocalPulumiCommand.createExceptionFromResult(LocalPulumiCommand.java:336)
	at com.pulumi.automation.LocalPulumiCommand.runInternal(LocalPulumiCommand.java:245)
	at com.pulumi.automation.LocalPulumiCommand.run(LocalPulumiCommand.java:157)
	at com.pulumi.automation.Workspace.runCommand(Workspace.java:562)
	at com.pulumi.automation.WorkspaceStack.runCommand(WorkspaceStack.java:913)
	at com.pulumi.automation.WorkspaceStack.refresh(WorkspaceStack.java:696)
	at org.example.App.main(App.kt:35)

Output of pulumi about

CLI
Version 3.209.0
Go Version go1.25.4
Go Compiler gc

Host
OS darwin
Version 15.7.2
Arch arm64

Additional context

No response

Contributing

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To contribute a fix for this issue, leave a comment (and link to your pull request, if you've opened one already).

Start with the reproduction in src/main/kotlin/org/example/App.kt, especially the LocalWorkspace.createOrSelectStack call and the PULUMI_RUN_PROGRAM=true path. Run the example and trace the package-requirements discovery that reports the missing sbt executable. Done means the refresh succeeds with PULUMI_RUN_PROGRAM=true in the provided reproduction without requiring an unavailable sbt command.