Bitcoin Core v30.0 Released

This version indicates the termination of support for versions 27.x and older, urging users to upgrade to continue receiving maintenance updates. Notably, this release addresses five low severity vulnerabilities while confirming that no medium or high severity vulnerabilities were fixed in the preceding version 28.0. For users on older versions, upgrading involves shutting down their current version and either running the installer on Windows or copying the files over on macOS or Linux. The process may require time, especially if migrating data directories is necessary. It ensures compatibility across Linux Kernel 3.17+, macOS 13+, and Windows 10+, although it advises against use on unsupported systems due to decreased testing frequency. Among the key updates, policy adjustments have been made to prepare for future deployments, including limiting legacy signature operations in a single transaction and increasing the default -datacarriersize to allow for more data carrier outputs. The introduction of the bitcoin command line tool is a highlight, offering greater accessibility and convenience for users with synonyms for existing commands and a new experimental IPC Mining Interface. Installation changes include relocating certain executables to the libexec/ directory. Technical adjustments necessitate re syncing with the coinstatsindex implementation upon first upgrade use. Modifications to logging practices and RPC updates signal a shift towards better resource management and reliance on fee estimation for transactions. The wallet functionality phase-out of BDB legacy wallets in favor of the descriptor wallet format and the GUI's transition to Qt 6, which supports dark mode on Windows and utilizes the Metal backend on macOS, are also notable. In addition to the comprehensive upgrades and changes within Bitcoin Core v30.0, there was an inquiry regarding alterations in the handling of the chainstate, as evidenced by a noticeable size difference in gigabytes. The observation pointed to a rapid temporary change in the size of the chainstate directory, contrasting with previous versions. However, subsequent communication clarified that the observed fluctuations returned to normal, suggesting the changes were not significant or permanent. The comparison of disk usage (du) lines before and after the upgrade, as captured in provided URLs, initially indicated a discrepancy but ultimately showed a restoration to expected sizes, concluding the issue as noise rather than a systemic change in the handling of the chainstate within this release. For those seeking detailed information on the upgrade process and the full spectrum of changes, the official GitHub page remains the primary resource.