Problem

The duplicate-detection lock files had non-deterministic variable order changes because environment variables were not sorted when building Docker arguments for container-based MCP servers. Since Go maps have random iteration order, compiling the same workflow multiple times would produce lock files with different -e KEY flag orderings, even though the functionality was identical.

Solution

Added alphabetical sorting of environment variable keys before building the Docker args list in two locations:

1. pkg/parser/mcp.go - In ParseMCPConfig() when handling container-based MCP configurations
2. pkg/workflow/mcp-config.go - In getMCPConfig() when transforming container fields to Docker commands

Both locations now collect env var keys into a slice, sort them alphabetically using sort.Strings(), then iterate over the sorted keys to build the args list. This ensures deterministic lock file generation.

Example

Given a workflow with environment variables:

mcp-servers:
  test-server:
    container: example/test:latest
    env:
      ZEBRA_VAR: "z"
      ALPHA_VAR: "a"
      BETA_VAR: "b"

Before: Args list had random order (e.g., [..., "-e", "ZEBRA_VAR", "-e", "ALPHA_VAR", "-e", "BETA_VAR", ...])

After: Args list has consistent alphabetical order ([..., "-e", "ALPHA_VAR", "-e", "BETA_VAR", "-e", "ZEBRA_VAR", ...])

Testing

• Existing TestMCPEnvVarsAlphabeticallySorted test validates the fix
• Created deterministic compilation test that compiles the same workflow 5 times and verifies identical output
• All 59 workflow files recompiled successfully with consistent ordering
• Full test suite passes (make test and make agent-finish)

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.