What causes "{name} could not be downloaded, {error}" in composer/composer?

Cache valid SVN credentials or provide them interactively (run svn ls manually to authenticate)

composer/composer · error · RuntimeException

{name} could not be downloaded, {error}

Error message

{name} could not be downloaded, {error}

What it means

Thrown by SvnDownloader::execute() (line 119-125) wrapping any RuntimeException from SvnUtil::execute() during svn co/switch. It prefixes the package pretty name and re-throws with the underlying svn error message, covering authentication, network, and repository-access failures.

Source

Thrown at src/Composer/Downloader/SvnDownloader.php:122

    /**
     * Execute an SVN command and try to fix up the process with credentials
     * if necessary.
     *
     * @param  string            $baseUrl Base URL of the repository
     * @param  non-empty-list<string> $command SVN command to run
     * @param  string            $url     SVN url
     * @param  string            $cwd     Working directory
     * @param  string            $path    Target for a checkout
     * @throws \RuntimeException
     */
    protected function execute(PackageInterface $package, string $baseUrl, array $command, string $url, ?string $cwd = null, ?string $path = null): string
    {
        $util = new SvnUtil($baseUrl, $this->io, $this->config, $this->process);
        $util->setCacheCredentials($this->cacheCredentials);
        try {
            return $util->execute($command, $url, $cwd, $path, $this->io->isVerbose());
        } catch (\RuntimeException $e) {
            throw new \RuntimeException(
                $package->getPrettyName().' could not be downloaded, '.$e->getMessage()
            );
        }
    }

    /**
     * @inheritDoc
     */
    protected function cleanChanges(PackageInterface $package, string $path, bool $update): PromiseInterface
    {
        if (null === ($changes = $this->getLocalChanges($package, $path))) {
            return \React\Promise\resolve(null);
        }

        if (!$this->io->isInteractive()) {
            if (true === $this->config->get('discard-changes')) {
                return $this->discardChanges($path);
            }

View on GitHub (pinned to 6ffc117740)

Solutions

Cache valid SVN credentials or provide them interactively (run svn ls <url> manually to authenticate)
Verify network/VPN connectivity to the SVN server from the environment
Confirm the repository url and path are correct and accessible
Check svn-cache-credentials repository setting if credential caching is the issue

Example fix

# authenticate and cache credentials once
svn ls https://svn.example.com/repo --username me
# then re-run
composer update

Defensive patterns

Strategy: try-catch

Try / catch

try {
    $downloader->download($package, $path);
} catch (\RuntimeException $e) {
    if (str_contains($e->getMessage(), 'could not be downloaded')) {
        // surface credential/network guidance; optionally prompt for svn creds and retry
        handleSvnAccessFailure($package, $e);
    } else { throw $e; }
}

Prevention

Cache SVN credentials once via 'svn ls <url>' before running composer
Ensure VPN/network connectivity to the SVN server in CI
Verify repository urls and access permissions in the repository definition

When it happens

Trigger: execute() calls $util->execute($command, $url, ...) for an svn checkout/switch and the underlying util throws — bad credentials, unreachable host, forbidden path, or a malformed svn url.

Common situations: SVN credentials not cached/wrong; repository behind a VPN/firewall that is not connected; svn url typo; server-side permission denial.

Related errors

AI-assisted analysis of composer/composer@6ffc117740 (2026-08-07). Data as JSON: /api/errors/b170876af61e6711. Report an issue: GitHub.