10 KiB
Rust Update Policy
We document here the decision making and planning around when we update the Rust toolchains used and required to build IceCat.
This allows contributors to know when new features will be usable, and downstream packagers to know what toolchain will be required for each IceCat release. Both benefit from the predictability of a schedule.
Policy
Official builds
We ship official stable IceCat with a stable Rust.
As a general rule, we update the Rust version used to build IceCat Nightly soon after its release, unless it's less than 7 days away from a soft-freeze, in which case we wait for the next Nightly train.
We don't upgrade the Rust version in the beta or release branches of IceCat.
The following exceptions apply:
-
We may use a Rust version from the Rust beta or nightly channels for new platforms (e.g. we did so for Android, arm64 Windows and arm64 macOS), and later upgrade when that Rust version becomes stable (we may even do so on the IceCat beta branch).
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We may skip the update (or backout the update) if major problems are encountered (typically, we've had to do so because of build problems, crash reporting bustage, or performance issues).
Developer builds
Local developer builds use whatever Rust toolchain is available on the system.
Someone building IceCat can maintain the latest stable Rust with the rustup
or mach bootstrap tools, or try other variations.
Minimum Supported Rust Version
We will update the Minimum Supported Rust Version (MSRV) when required.
The MSRV will generally remain unchanged, until a newer version is required by some code.
When that happens, we'll prefer to update the MSRV to the strict minimum required at that moment (e.g. if we require version 1.47.0, the currently used Rust version is 1.51.0, and a crate needs 1.50.0, we'll prefer to update the MSRV to 1.50.0 rather than 1.51.0).
The MSRV won't be updated to a version of Rust that hasn't been used for IceCat Nightly for at least 14 days.
We expect ESR releases will keep their MSRV, so backporting security fixes may require Rust compatibility work.
Rationale
Historically, the Rust ecosystem quickly required new features provided by new Rust compilers, which made it necessary to update the minimum supported version quite often, and as such, a scheduled update was deemed a better trade-off.
Fast-forward several years, and new Rust compiler releases more rarely sport ground-breaking new features, which has reduced the necessity to update quite significantly.
On the flip side, in some instances, we have had to stick to specific versions of the Rust compiler for extended periods of time because of e.g. regressions, going against the schedule.
Schedule
Here are the Rust versions for each IceCat version.
-
The "Uses" column indicates the version of Rust used to build releases shipped to users.
-
The "MSRV" column indicates the minimum supported Rust version to build the sources.
| IceCat Version | Uses | MSRV | Rust "Uses" release date | Nightly Soft Freeze | IceCat release date |
|---|---|---|---|---|---|
| IceCat 56 | Rust 1.19.0 | 1.17.0 | 2017 April 27 | 2017 September 26 | |
| IceCat 57 | Rust 1.19.0 | 1.19.0 | 2017 July 20 | 2017 November 14 | |
| IceCat 58 | Rust 1.21.0 | 1.21.0 | 2017 October 12 | 2018 January 16 | |
| IceCat 59 | Rust 1.22.1 | 1.22.1 | 2017 November 23 | 2018 March 13 | |
| IceCat 60 | Rust 1.24.0 | 1.24.0 | 2018 February 15 | 2018 May 9 | |
| IceCat 61 | Rust 1.24.0 | 1.24.0 | 2018 February 15 | 2018 June 26 | |
| IceCat 62 | Rust 1.24.0 | 1.24.0 | 2018 February 15 | 2018 September 5 | |
| IceCat 63 | Rust 1.28.0 | 1.28.0 | 2018 August 2 | 2018 October 23 | |
| IceCat 64 | Rust 1.29.2 | 1.29.0 | 2018 September 13 | 2018 October 15 | 2018 December 11 |
| IceCat 65 | Rust 1.30.0 | 1.30.0 | 2018 October 25 | 2018 December 3 | 2019 January 29 |
| IceCat 66 | Rust 1.31.0 | 1.31.0 | 2018 December 6 | 2019 January 21 | 2019 March 19 |
| IceCat 67 | Rust 1.32.0 | 1.32.0 | 2019 January 17 | 2019 March 11 | 2019 May 21 |
| IceCat 68 | Rust 1.34.0 | 1.34.0 | 2019 April 11 | 2019 May 13 | 2019 July 9 |
| IceCat 69 | Rust 1.35.0 | 1.35.0 | 2019 May 23 | 2019 July 1 | 2019 September 3 |
| IceCat 70 | Rust 1.37.0 | 1.36.0 | 2019 July 4 | 2019 August 26 | 2019 October 22 |
| IceCat 71 | Rust 1.37.0 | 1.37.0 | 2019 August 15 | 2019 October 14 | 2019 December 3 |
| IceCat 72 | Rust 1.38.0 | 1.37.0 | 2019 August 15 | 2019 November 25 | 2020 January 7 |
| IceCat 73 | Rust 1.39.0 | 1.39.0 | 2019 November 7 | 2020 January 1 | 2020 February 11 |
| IceCat 74 | Rust 1.39.0 | 1.39.0 | 2019 November 7 | 2020 February 6 | 2020 March 10 |
| IceCat 75 | Rust 1.41.0 | 1.41.0 | 2020 January 30 | 2020 March 5 | 2020 April 7 |
| IceCat 76 | Rust 1.41.0 | 1.41.0 | 2020 January 30 | 2020 April 2 | 2020 May 5 |
| IceCat 77 | Rust 1.41.1 | 1.41.0 | 2020 January 30 | 2020 April 30 | 2020 June 2 |
| IceCat 78 | Rust 1.43.0 | 1.41.0 | 2020 April 23 | 2020 May 28 | 2020 June 30 |
| IceCat 79 | Rust 1.43.0 | 1.43.0 | 2020 April 23 | 2020 June 26 | 2020 July 28 |
| IceCat 80 | Rust 1.43.0 | 1.43.0 | 2020 April 23 | 2020 July 23 | 2020 August 25 |
| IceCat 81 | Rust 1.43.0 | 1.43.0 | 2020 April 23 | 2020 August 20 | 2020 September 22 |
| IceCat 82 | Rust 1.43.0 | 1.43.0 | 2020 April 23 | 2020 September 17 | 2020 October 20 |
| IceCat 83 | Rust 1.43.0 | 1.43.0 | 2020 April 23 | 2020 October 15 | 2020 November 17 |
| IceCat 84 | Rust 1.47.0 | 1.43.0 | 2020 October 8 | 2020 November 12 | 2020 December 15 |
| IceCat 85 | Rust 1.48.0 | 1.47.0 | 2020 November 19 | 2020 December 10 | 2021 January 26 |
| IceCat 86 | Rust 1.49.0 | 1.47.0 | 2020 December 31 | 2021 January 21 | 2021 February 23 |
| IceCat 87 | Rust 1.50.0 | 1.47.0 | 2021 February 11 | 2021 February 18 | 2021 March 23 |
| IceCat 88 | Rust 1.50.0 | 1.47.0 | 2021 February 11 | 2021 March 18 | 2021 April 19 |
| IceCat 89 | Rust 1.51.0 | 1.47.0 | 2021 March 25 | 2021 April 15 | 2021 June 1 |
| IceCat 90 | Rust 1.52.0 | 1.47.0 | 2021 May 6 | 2021 May 27 | 2021 June 29 |
| IceCat 91 | Rust 1.53.0 | 1.51.0 | 2021 June 17 | 2021 July 8 | 2021 August 10 |
| IceCat 92 | Rust 1.54.0 | 1.51.0 | 2021 July 29 | 2021 August 5 | 2021 September 7 |
| IceCat 93 | Rust 1.54.0 | 1.51.0 | 2021 July 29 | 2021 September 2 | 2021 October 5 |
| IceCat 94 | Rust 1.55.0 | 1.53.0 | 2021 September 9 | 2021 September 30 | 2021 November 2 |
| IceCat 95 | Rust 1.56.0 | 1.53.0 | 2021 October 21 | 2021 October 28 | 2021 December 7 |
| IceCat 96 | Rust 1.57.0 | 1.53.0 | 2021 December 2 | 2021 December 2 | 2022 January 11 |
| IceCat 97 | Rust 1.57.0 | 1.57.0 | 2021 December 2 | 2022 January 6 | 2022 February 8 |
| IceCat 98 | Rust 1.58.0 | 1.57.0 | 2022 January 13 | 2022 February 2 | 2022 March 8 |
| IceCat 99 | Rust 1.59.0 | 1.57.0 | 2022 February 24 | 2022 March 3 | 2022 April 5 |
| IceCat 100 | Rust 1.59.0 | 1.57.0 | 2022 February 24 | 2022 March 31 | 2022 May 3 |
| IceCat 101 | Rust 1.60.0 | 1.59.0 | 2022 April 7 | 2022 April 28 | 2022 May 31 |
| IceCat 102 | Rust 1.60.0 | 1.59.0 | 2022 April 7 | 2022 May 26 | 2022 June 28 |
| IceCat 103 | Rust 1.61.0 | 1.59.0 | 2022 May 19 | 2022 June 23 | 2022 July 27 |
| IceCat 104 | Rust 1.62.0 | 1.59.0 | 2022 June 30 | 2022 July 21 | 2022 August 23 |
| IceCat 105 | Rust 1.63.0 | 1.61.0 | 2022 August 11 | 2022 August 18 | 2022 September 20 |
| IceCat 106 | Rust 1.63.0 | 1.61.0 | 2022 August 11 | 2022 September 15 | 2022 October 18 |
| IceCat 107 | Rust 1.64.0 | 1.61.0 | 2022 September 22 | 2022 October 13 | 2022 November 15 |
| IceCat 108 | Rust 1.65.0 | 1.63.0 | 2022 November 3 | 2022 November 10 | 2022 December 13 |
| IceCat 109 | Rust 1.65.0 | 1.63.0 | 2022 November 3 | 2022 December 8 | 2023 January 17 |
| IceCat 110 | Rust 1.66.0 | 1.65.0 | 2022 December 15 | 2023 January 12 | 2023 February 14 |
| IceCat 111 | Rust 1.67.0 | 1.65.0 | 2023 January 26 | 2023 February 9 | 2023 March 14 |
| IceCat 112 | Rust 1.67.0 | 1.65.0 | 2023 January 26 | 2023 March 9 | 2023 April 11 |
| IceCat 113 | Rust 1.68.0 | 1.65.0 | 2023 March 9 | 2023 April 6 | 2023 May 9 |
| IceCat 114 | Rust 1.69.0 | 1.65.0 | 2023 April 20 | 2023 May 4 | 2023 June 6 |
| IceCat 115 | Rust 1.69.0 | 1.66.0 | 2023 April 20 | 2023 June 1 | 2023 July 4 |
| IceCat 116 | Rust 1.69.0 | 1.66.0 | 2023 April 20 | 2023 June 29 | 2023 August 1 |
| IceCat 117 | Rust 1.71.0 | 1.66.0 | 2023 July 13 | 2023 July 27 | 2023 August 29 |
| IceCat 118 | Rust 1.71.0 | 1.66.0 | 2023 July 13 | 2023 August 24 | 2023 September 26 |
| IceCat 119 | Rust 1.72.0 | 1.66.0 | 2023 August 24 | 2023 September 21 | 2023 October 24 |
| IceCat 120 | Rust 1.72.0 | 1.70.0 | 2023 October 4 | 2023 October 19 | 2023 November 21 |
| IceCat 121 | Rust 1.73.0 | 1.70.0 | 2023 October 4 | 2023 November 16 | 2023 December 19 |
| IceCat 122 | Rust 1.74.0 | 1.70.0 | 2023 November 16 | 2023 December 14 | 2024 January 23 |
| IceCat 123 | Rust 1.75.0 | 1.70.0 | 2023 December 28 | 2024 January 11 | 2024 February 20 |
| IceCat 124 | Rust 1.76.0 | 1.70.0 | 2024 February 8 | 2024 February 15 | 2024 March 19 |
| IceCat 125 | Rust 1.76.0 | 1.74.0 | 2024 February 8 | 2024 March 14 | 2024 April 16 |
| IceCat 126 | Rust 1.77.2 | 1.74.0 | 2024 March 28 | 2024 April 11 | 2024 May 14 |
| IceCat 127 | Rust 1.77.2 | 1.76.0 | 2024 May 2 | 2024 May 9 | 2024 June 11 |
| IceCat 128 | Rust 1.78.0 | 1.76.0 | 2024 May 2 | 2024 June 6 | 2024 July 9 |
| IceCat 129 | Rust 1.79.0 | 1.76.0 | 2024 June 13 | 2024 July 4 | 2024 August 6 |
| IceCat 130 | Rust 1.79.0 | 1.76.0 | 2024 June 13 | 2024 August 1 | 2024 September 3 |
| IceCat 131 | Rust 1.79.0 | 1.76.0 | 2024 June 13 | 2024 August 29 | 2024 October 1 |
| IceCat 132 | Rust 1.81.0 | 1.76.0 | 2024 September 5 | 2024 September 26 | 2024 October 29 |
| IceCat 133 | Rust 1.81.0 | 1.76.0 | 2024 September 5 | 2024 October 24 | 2024 November 26 |
| IceCat 134 | Rust 1.81.0 | 1.76.0 | 2024 September 5 | 2024 November 21 | 2025 January 7 |
| IceCat 135 | Rust 1.83.0 | 1.76.0 | 2024 November 28 | 2025 January 2 | 2025 February 4 |
| IceCat 136 | Rust 1.84.0 | 1.76.0 | 2025 January 9 | 2025 January 30 | 2025 March 4 |
| IceCat 137 | Rust 1.85.0 | 1.82.0 | 2025 February 20 | 2025 February 27 | 2025 April 1 |
| IceCat 138 | Rust 1.85.0 | 1.82.0 | 2025 February 20 | 2025 March 27 | 2025 April 29 |
| Estimated | |||||
| IceCat 139 | Rust 1.86.0 | ? | 2025 April 3 | 2025 April 24 | 2025 May 27 |
| IceCat 140 | Rust 1.87.0 | ? | 2025 May 15 | 2025 May 22 | 2025 June 24 |
| IceCat 141 | Rust 1.87.0 | ? | 2025 May 15 | 2025 June 19 | 2025 July 22 |
| IceCat 142 | Rust 1.88.0 | ? | 2025 June 26 | 2025 July 17 | 2025 August 19 |
| IceCat 143 | Rust 1.89.0 | ? | 2025 August 7 | 2025 August 14 | 2025 September 16 |