Umbrella issue for 26.0 testing. Please help testing on a wide variety of supported platforms, as well as interaction with different software.

Let us know which version you tested on which operating system.

If you find an issue, please search Github for known issues first and then open a new Github issue.

*This meta issue should not be used to report bugs, as a single thread makes it impossible to track more than one topic.*

See [26.0 Draft Release Notes](https://github.com/bitcoin-core/bitcoin-devwiki/wiki/26.0-Release-Notes-Draft) for a list of changes.

See here for the testing guide: https://github.com/bitcoin-core/bitcoin-devwiki/wiki/26.0-Release-Candidate-Testing-Guide.
* @sa ChainstateManager::PopulateAndValidateSnapshot()
     */
    void EmplaceCoinInternalDANGER(COutPoint&& outpoint, Coin&& coin);
    /**
     * Spend a coin. Pass moveto in order to get the deleted data.
     * If no unspent output exists for the passed outpoint, this call
     * has no effect.
     */
    bool SpendCoin(const COutPoint &outpoint, Coin* moveto = nullptr);
    /**
     * Push the modifications applied to this cache to its base and wipe local state.
     * Failure to call this method or Sync() before destruction will cause the changes
     * to be forgotten.
     * If false is returned, the state of this cache (and its backing view) will be undefined.
     */
    bool Flush();
    /**
     * Push the modifications applied to this cache to its base while retaining
     * the contents of this cache (except for spent coins, which we erase).
     * Failure to call this method or Flush() before destruction will cause the changes
     * to be forgotten.
     * If false is returned, the state of this cache (and its backing view) will be undefined.
     */
    bool Sync();
    /**
     * Removes the UTXO with the given outpoint from the cache, if it is
     * not modified.
     */
    void Uncache(const COutPoint &outpoint);