fix(core): add env var to disable fetching migration metadata from registry (#32850)

Add a new `NX_MIGRATE_SKIP_REGISTRY_FETCH` environment variable to opt
out of fetching package versions and migrations metadata from the
registry and instead, use package installation to get the information.

Author: leosvelperez

astro-docs/src/content/docs/reference/environment-variables.mdoc

@@ -41,6 +41,7 @@ The following environment variables are ones that you can set to change the beha
 | `NX_BATCH_MODE`                    | boolean        | If set to `true`, Nx will run task(s) in batches for executors which support batches.                                                                                                                                               |
 | `NX_SKIP_LOG_GROUPING`             | boolean        | If set to `true`, Nx will not group command's logs on CI.                                                                                                                                                                           |
 | `NX_MIGRATE_CLI_VERSION`           | string         | The version of Nx to use for running the `nx migrate` command. If not set, it defaults to `latest`.                                                                                                                                 |
+| NX_MIGRATE_SKIP_REGISTRY_FETCH     | boolean        | If set to `true`, will skip fetching metadata from the registry and instead use the installation method directly.                                                                                                                   |
 | `NX_LOAD_DOT_ENV_FILES`            | boolean        | If set to 'false', Nx will not load any environment files (e.g. `.local.env`, `.env.local`)                                                                                                                                         |
 | `NX_MAX_CACHE_SIZE`                | string         | Alternative to configuring `maxCacheSize` in `nx.json`. Defines the maximum size of the local task cache. See [`maxCacheSize`](/docs/reference/nx-json#max-cache-size) for supported units and behavior details.                    |
 | `NX_NATIVE_FILE_CACHE_DIRECTORY`   | string         | The cache for native `.node` files is stored under a global temp directory by default. Set this variable to use a different directory. This is interpreted as an absolute path.                                                     |

docs/shared/reference/environment-variables.md

@@ -38,6 +38,7 @@ The following environment variables are ones that you can set to change the beha
 | NX_BATCH_MODE                    | boolean        | If set to `true`, Nx will run task(s) in batches for executors which support batches.                                                                                                                                          |
 | NX_SKIP_LOG_GROUPING             | boolean        | If set to `true`, Nx will not group command's logs on CI.                                                                                                                                                                      |
 | NX_MIGRATE_CLI_VERSION           | string         | The version of Nx to use for running the `nx migrate` command. If not set, it defaults to `latest`.                                                                                                                            |
+| NX_MIGRATE_SKIP_REGISTRY_FETCH   | boolean        | If set to `true`, will skip fetching metadata from the registry and instead use the installation method directly.                                                                                                              |
 | NX_LOAD_DOT_ENV_FILES            | boolean        | If set to 'false', Nx will not load any environment files (e.g. `.local.env`, `.env.local`)                                                                                                                                    |
 | NX_MAX_CACHE_SIZE                | string         | Alternative to configuring `maxCacheSize` in `nx.json`. Defines the maximum size of the local task cache. See [`maxCacheSize`](/reference/nx-json#max-cache-size) for supported units and behavior details.                    |
 | NX_NATIVE_FILE_CACHE_DIRECTORY   | string         | The cache for native `.node` files is stored under a global temp directory by default. Set this variable to use a different directory. This is interpreted as an absolute path.                                                |

packages/nx/src/command-line/migrate/migrate.ts

@@ -926,6 +926,12 @@ function createFetcher() {
     packageVersion,
     setCache: (packageName: string, packageVersion: string) => void
   ): Promise<ResolvedMigrationConfiguration> {
+    if (process.env.NX_MIGRATE_SKIP_REGISTRY_FETCH === 'true') {
+      // Skip registry fetch and use installation method directly
+      logger.info(`Fetching ${packageName}@${packageVersion}`);
+      return getPackageMigrationsUsingInstall(packageName, packageVersion);
+    }
+
     const cacheKey = packageName + '-' + packageVersion;
     return Promise.resolve(resolvedVersionCache[cacheKey])
       .then((cachedResolvedVersion) => {