MPS 2026.2 release candidate adds Linux ARM64 builds, including standalone RCPs

Start with the build script. Regenerating it in the Build Script Wizard adds a Linux ARM64 distribution next to the existing platform distributions ^[4]. That is the shortest route to an ARM64 artifact you can test.

The post says MPS itself ships with a matching bundled JetBrains Java Runtime ^[2]. It does not say whether standalone RCPs bundle the same runtime, which bundled plugins carry ARM64 native libraries, or when the final build lands.

The TAR import is where packaging gets easier. The new `import files from tar` and `files from tar` entries read plain TAR, gzip and bzip2 archives ^[5][6]. The source can be an archive file or another TAR layout defined in the same build script ^[6]. Into a TAR layout, symbolic links and file permissions are preserved ^[7].

The old behaviour was the problem. Symbolic links were sometimes replaced with copies of their targets, so large native libraries were included more than once, particularly on macOS ^[8]. A duplicated native library is the kind of bug that shows up only as a bigger download.

The macOS fix changes a file name. Archive distributions now use .tar.gz instead of .zip, and the wizard generates the same format for standalone macOS applications ^[9]. JetBrains made the change to preserve symbolic links ^[9]. In our view, any release script that fetches, names or unpacks the macOS .zip will need an edit before it meets this build. That is the one adoption cost we can see from the post.

The same RC carries a rework of the Projectional Agent Toolkit. JetBrains says that in its measurements with Claude Code and Opus 5 and 5.5, token savings exceeded 50% on common tasks such as DSL modeling or implementing language definitions ^[11]. That is JetBrains' own workload. The number would transfer to a team whose agents do the same modeling and language-definition work through the MPS MCP API.

Testing now means testing a candidate. JetBrains describes the build as a way to try the release ahead of its official launch ^[1], and says it improves on the 2026.2 EAP1 build ^[10].