Error: Inconsistent dependency lock file: "no version is selected" after adding a provider

TL;DR

Your .terraform.lock.hcl does not cover a provider your configuration now requires. That happens when you add a provider (or a module that needs one) after the last terraform init. Run terraform init -upgrade to record the new selection, commit the lock file, and move on.

The error

Error: Inconsistent dependency lock file

- provider registry.terraform.io/hashicorp/random: required by this
  configuration but no version is selected

Another common shape:

Error: Inconsistent dependency lock file. The following dependency selections recorded in the lock file are inconsistent...

Steps to fix

1. Confirm the cause: you (or a merged PR) added a provider to required_providers or added a module that pulls one in, without re-running init.

• Expected: git log --oneline -3 -- .terraform.lock.hcl shows the lock file is older than the config change.

1. Run terraform init -upgrade.

• Expected: Terraform selects versions for the new providers and rewrites .terraform.lock.hcl. init succeeds.

1. Commit the updated .terraform.lock.hcl.

• Expected: git status shows the lock file modified; CI will now use the same selections.

1. Run terraform plan to confirm everything resolves.

• Expected: plan starts without lock errors.

When to use this

• terraform init fails with Inconsistent dependency lock file after adding a provider, adding a module, or pulling a branch that did either.

When NOT to use this

• Failed to query available provider packages means the registry cannot satisfy your version constraints (a constraint problem, not a lock problem). If the lock file is committed and CI still fails, the committed file is stale: regenerate it locally and commit.

Compatibility

• Terraform 0.14+ (lock file introduced). -upgrade behavior is stable across 1.x.

Root cause

The lock file pins the exact provider versions and hashes your configuration resolved to. Adding a new provider requirement makes the recorded selections incomplete, and Terraform refuses to guess: it errors rather than silently picking a version that might differ from what a teammate gets.

Edge cases

• If your repo gitignores .terraform.lock.hcl, every fresh clone re-resolves and you lose reproducibility; commit the lock file instead.
• terraform init -upgrade upgrades everything; to add one provider without moving others, temporarily narrow with -upgrade=false is not possible, so review the plan diff after upgrading.
• With dev_overrides in the CLI config, Terraform skips lock entries for those providers (1.16+ warns about it).