 ```ts
import { Error } from 'typescript'; // Assuming TypeScript's built-in Error type is used

export function parseSemver(version: string): { major: number; minor: number; patch: number; prerelease: string | null; build: string | null } {
    const regex = /^(\d+)\.(\d+)\.(\d+)(?:-(.+))?(?:\+(.+))?$/;
    const match = version.match(regex);

    if (!match) {
        throw new Error(`Invalid semver format: ${version}`);
    }

    const [, major, minor, patch, prerelease, build] = match;

    if (major === undefined || minor === undefined || patch === undefined) {
        throw new Error(`Invalid semver format: ${version}`);
    }

    return {
        major: parseInt(major, 10),
        minor: parseInt(minor, 10),
        patch: parseInt(patch, 10),
        prerelease: prerelease || null,
        build: build || null,
    };
}
```