langflow issue when build from source via docker and compose

The problem

Reported in Langflow: langflow issue when build from source via docker and compose.

The fix

Building langflow from source with a custom Dockerfile fails at uv sync because the codebase is now a uv workspace with four members: src/backend/base, src/lfx, src/sdk, and the root. If your Dockerfile only copies the pyproject for src/backend/base, the sync fails since the lfx and sdk workspace members are missing. Copy all four workspace members (their pyproject.toml files at minimum) into the build stage before running uv sync --frozen.

In gh:langflow-ai/langflow#8296 (https://github.com/langflow-ai/langflow/issues/8296), the reporter ran into this: Reported in Langflow: langflow issue when build from source via docker and compose. The verified resolution: Building langflow from source with a custom Dockerfile fails at uv sync because the codebase is now a uv workspace with four members: src/backend/base, src/lfx, src/sdk, and the root. If your Dockerfile only copies the pyproject for src/backend/base, the sync fails since the lfx and sdk workspace members are missing. Copy all four workspace members (their pyproject.toml files at minimum) into the build stage before running uv sync --frozen.