[Conda] Error: CondaDependencyError — failed to resolve package dependencies — How to Fix It
Summary The CondaDependencyError: failed to resolve package dependencies occurs when Conda’s solver cannot find a set of compatible package versions that meet all requirements. It often arises from conflicting version constraints, mixed channels (like defaults and conda-forge), or outdated metadata. The solution is to relax constraints, update Conda, or broaden your available repositories. Context Conda uses a dependency solver to ensure every installed package is compatible with the others in your environment. When two or more dependencies have incompatible version requirements — or when metadata is outdated — the solver fails. This issue is especially common when using strict version pins, old YAML environment files, or mixing channels with divergent dependency trees. Probable Cause Strict version pins such as python=3.9.0 or numpy=1.21.0 blocking compatible builds. Mixing the defaults and conda-forge channels without priority control. Outdated or corrupted Con...