Release Notes
Released on 2026-03-23.
Breaking changes
This release includes changes to the networking stack used by uv. While we think that breakage will be rare, it is possible that these changes will result in the rejection of certificates previously trusted by uv so we have marked the change as breaking out of an abundance of caution.
The changes are largely driven by the upgrade of reqwest, which powers uv's HTTP clients, to v0.13 which included some breaking changes to TLS certificate verification.
The following changes are included:
-
rustls-platform-verifieris used instead ofrustls-native-certsandwebpkifor certificate verificationThis change should have no effect unless you are using the
native-tlsoption to enable reading system certificates.rustls-platform-verifierdelegates to the system for certificate validation (e.g.,Security.frameworkon macOS) instead of eagerly loading certificates from the system and verifying them viawebpki. The effects of this change will vary based on the operating system. In general, uv's certificate validation should now be more consistent with browsers and other native applications. However, this is the most likely cause of breaking changes in this release. Some previously failing certificate chains may succeed, and some previously accepted certificate chains may fail. In either case, we expect the validation to be more correct and welcome reports of regressions.In particular, because more responsibility for validating the certificate is transferred to your system's security library, some features like CA constraints or revocation of certificates via OCSP and CRLs may now be used.
This change should improve performance when using system certificate on macOS, as uv no longer needs to load all certificates from the keychain at startup.
-
aws-lcis used instead ofringfor a cryptography backendThere should not be breaking changes from this change. We expect this to expand support for certificate signature algorithms.
-
--native-tlsis deprecated in favor of a new--system-certsflagThe
--native-tlsflag is still usable and has identical behavior to--system-certs.This change was made to reduce confusion about the TLS implementation uv uses. uv always uses
rustlsnotnative-tls. -
Building uv on x86-64 and i686 Windows requires NASM
NASM is required by
aws-lc. If not found on the system, a prebuilt blob provided byaws-lc-syswill be used.If you are not building uv from source, this change has no effect.
See the CONTRIBUTING guide for details.
-
Empty
SSL_CERT_FILEvalues are ignored (for consistency withSSL_CERT_DIR)
See #18550 for details.
Python
- Enable frame pointers for improved profiling on Linux x86-64 and aarch64
See the python-build-standalone release notes for details.
Enhancements
- Treat 'Dynamic' values as case-insensitive (#18669)
- Use a dedicated error for invalid cache control headers (#18657)
- Enable checksum verification in the generated installer script (#18625)
Preview features
- Add
--service-formatand--service-urltouv audit(#18571)
Performance
- Avoid holding flat index lock across indexes (#18659)
Bug fixes
- Find the dynamic linker on the file system when sniffing binaries fails (#18457)
- Fix export of conflicting workspace members with dependencies (#18666)
- Respect installed settings in
uv tool list --outdated(#18586) - Treat paths originating as PEP 508 URLs which contain expanded variables as relative (#18680)
- Fix
uv exportfor workspace member packages with conflicts (#18635) - Continue to alternative authentication providers when the pyx store has no token (#18425)
- Use redacted URLs for log messages in cached client (#18599)
Documentation
- Add details on Linux versions to the platform policy (#18574)
- Clarify
FLASH_ATTENTION_SKIP_CUDA_BUILDguidance forflash-attninstalls (#18473) - Split the dependency bots page into two separate pages (#18597)
- Split the alternative indexes page into separate pages (#18607)
Install uv 0.11.0
Install prebuilt binaries via shell script
curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/uv/releases/download/0.11.0/uv-installer.sh | shInstall prebuilt binaries via powershell script
powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/uv/releases/download/0.11.0/uv-installer.ps1 | iex"Download uv 0.11.0
Verifying GitHub Artifact Attestations
The artifacts in this release have attestations generated with GitHub Artifact Attestations. These can be verified by using the GitHub CLI:
gh attestation verify <file-path of downloaded artifact> --repo astral-sh/uvYou can also download the attestation from GitHub and verify against that directly:
gh attestation verify <file-path of downloaded artifact> --bundle <file-path of downloaded attestation>