Rust part fails to build on riscv but passes on any other architecture (core22)
Metadata
Current evaluation
Closed by the reporter (2025-11-13) as a fluke: the core22/riscv rustup default-toolchain error never recurred in two weeks of builds; no snapcraft fix or commit was made.
Resolution: closed stale
Reason: Maintainers could not read the build logs and asked for re-upload, but the author reported the failure was transient (log links had expired) and asked to reopen if it reappears. No PR, commit, or code change addressed the rust-plugin riscv toolchain error, and the issue sat labelled 'Status: Needs information' before being closed.
Evaluated by: mr-cal-bot
No scores available.
Issue body
### Bug Description
Building the same part on different architecture fails on riscv core22 with the following error: [(full log here)](https://productionresultssa18.blob.core.windows.net/actions-results/f013c6d2-eec4-474e-977b-92d2705547ce/workflow-job-run-9bd539c9-7a37-560d-a3ef-4bfef2c9a695/logs/job/job-logs.txt?rsct=text%2Fplain&se=2025-10-31T09%3A17%3A50Z&sig=fR%2FONdmcEpvuJ%2B1KHCF30Uwnov3kA0rFsogOLKOeJgs%3D&ske=2025-10-31T20%3A58%3A07Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2025-10-31T08%3A58%3A07Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2025-10-31T09%3A07%3A45Z&sv=2025-11-05)
```
2025-10-30T20:01:38.4843633Z Building gnome-randr[K
2025-10-30T20:01:38.5769595Z Generating build commands for .[K
2025-10-30T20:01:38.5774469Z :: + cargo read-manifest --manifest-path ./Cargo.toml[K
2025-10-30T20:01:40.0876637Z :: error: rustup could not choose a version of cargo to run, because one wasn't specified explicitly, and no default is configured.[K
2025-10-30T20:01:40.0883502Z :: help: run 'rustup default stable' to download the latest stable release of Rust and set it as your default toolchain.[K
2025-10-30T20:01:40.0973655Z :: + pushd .[K
2025-10-30T20:01:40.0994479Z :: /data/parts/gnome-randr/build /data/parts/gnome-randr/build[K
2025-10-30T20:01:40.1003909Z :: + cargo build --workspace --release[K
2025-10-30T20:01:41.5791354Z :: error: rustup could not choose a version of cargo to run, because one wasn't specified explicitly, and no default is configured.[K
```
While on armhf (for example, it works just fine) see: [build](https://productionresultssa18.blob.core.windows.net/actions-results/f013c6d2-eec4-474e-977b-92d2705547ce/workflow-job-run-0762c87b-ea41-5f67-bb95-f9806a6e98ed/logs/job/job-logs.txt?rsct=text%2Fplain&se=2025-10-31T09%3A41%3A07Z&sig=4FhOgkZHyGENXI%2BjzX4FU9KDTOicWmOWBMQIf84PU%2F0%3D&ske=2025-10-31T20%3A58%3A15Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2025-10-31T08%3A58%3A15Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2025-10-31T09%3A31%3A02Z&sv=2025-11-05)
> Note: the same exact part on riscv but on core24 builds just fine: [link](https://productionresultssa18.blob.core.windows.net/actions-results/f013c6d2-eec4-474e-977b-92d2705547ce/workflow-job-run-ac57f2af-dee8-5362-a883-0d49e32eef0b/logs/job/job-logs.txt?rsct=text%2Fplain&se=2025-10-31T12%3A41%3A28Z&sig=4MOV1EPag13ZcMPJhV6ACSMvplxn6TfWsyOk59%2FjcnA%3D&ske=2025-10-31T21%3A05%3A10Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2025-10-31T09%3A05%3A10Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2025-10-31T12%3A31%3A23Z&sv=2025-11-05)
### To Reproduce
Create a core22 snap with the following part:
```
gnome-randr:
source: https://github.com/maxwellainatchi/gnome-randr-rust.git
plugin: rust
rust-channel: nightly
build-packages:
- libdbus-1-dev
```
Build it on any architecture that is not riscv, it passes
Build it on riscv: it fails with the error above
### Environment
- snapcraft 8.12.0 (all builds for all architectures are on the same snapcraft version)
- canonical/snapcraft-multiarch-action@v1
- ubuntu-latest
### snapcraft.yaml
```yaml
base: core22
[...]
gnome-randr:
source: https://github.com/maxwellainatchi/gnome-randr-rust.git
plugin: rust
rust-channel: nightly
build-packages:
- libdbus-1-dev
[...]
```
### Relevant log output
```shell
2025-10-30T18:14:27.1954486Z snapcraft 8.12.0 from Canonical[32m✓[0m installed
[...]
2025-10-30T20:01:38.4843633Z Building gnome-randr�[K
2025-10-30T20:01:38.5769595Z Generating build commands for .�[K
2025-10-30T20:01:38.5774469Z :: + cargo read-manifest --manifest-path ./Cargo.toml�[K
2025-10-30T20:01:40.0876637Z :: error: rustup could not choose a version of cargo to run, because one wasn't specified explicitly, and no default is configured.�[K
2025-10-30T20:01:40.0883502Z :: help: run 'rustup default stable' to download the latest stable release of Rust and set it as your default toolchain.�[K
2025-10-30T20:01:40.0973655Z :: + pushd .�[K
2025-10-30T20:01:40.0994479Z :: /data/parts/gnome-randr/build /data/parts/gnome-randr/build�[K
2025-10-30T20:01:40.1003909Z :: + cargo build --workspace --release�[K
2025-10-30T20:01:41.5791354Z :: error: rustup could not choose a version of cargo to run, because one wasn't specified explicitly, and no default is configured.�[K
```
### Additional context
Failing build on [core22 riscv](https://productionresultssa18.blob.core.windows.net/actions-results/f013c6d2-eec4-474e-977b-92d2705547ce/workflow-job-run-9bd539c9-7a37-560d-a3ef-4bfef2c9a695/logs/job/job-logs.txt?rsct=text%2Fplain&se=2025-10-31T09%3A17%3A50Z&sig=fR%2FONdmcEpvuJ%2B1KHCF30Uwnov3kA0rFsogOLKOeJgs%3D&ske=2025-10-31T20%3A58%3A07Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2025-10-31T08%3A58%3A07Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2025-10-31T09%3A07%3A45Z&sv=2025-11-05)
Passing build on [core22 armhf](https://productionresultssa18.blob.core.windows.net/actions-results/f013c6d2-eec4-474e-977b-92d2705547ce/workflow-job-run-0762c87b-ea41-5f67-bb95-f9806a6e98ed/logs/job/job-logs.txt?rsct=text%2Fplain&se=2025-10-31T09%3A41%3A07Z&sig=4FhOgkZHyGENXI%2BjzX4FU9KDTOicWmOWBMQIf84PU%2F0%3D&ske=2025-10-31T20%3A58%3A15Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2025-10-31T08%3A58%3A15Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2025-10-31T09%3A31%3A02Z&sv=2025-11-05)
Passing build on [core24 riscv](https://productionresultssa18.blob.core.windows.net/actions-results/f013c6d2-eec4-474e-977b-92d2705547ce/workflow-job-run-ac57f2af-dee8-5362-a883-0d49e32eef0b/logs/job/job-logs.txt?rsct=text%2Fplain&se=2025-10-31T12%3A41%3A28Z&sig=4MOV1EPag13ZcMPJhV6ACSMvplxn6TfWsyOk59%2FjcnA%3D&ske=2025-10-31T21%3A05%3A10Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2025-10-31T09%3A05%3A10Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2025-10-31T12%3A31%3A23Z&sv=2025-11-05)
The snap part is unchanged, only thing that changes is the base.
Evaluation history
| Date | Model | Scores | Action | Summary |
|---|---|---|---|---|
| stealth/space-bunny-alpha | — | closed stale | Closed by the reporter (2025-11-13) as a fluke: the core22/riscv rustup default-toolchain error never recurred in two weeks of builds; no snapcraft fix or commit was made. | |
| stealth/space-bunny-alpha | — | closed stale | Closed after the reporter called the core22/riscv failure a fluke: it had not recurred during two weeks of builds. No fix PR or commit was linked. | |
| stealth/space-bunny-alpha | — | closed stale | Closed without a fix after the reporter said the core22/riscv failure had not recurred for two weeks and would reopen it if seen again. | |
| qwen/qwen3.6-35b-a3b | — | — | Closed as a transient issue. The author reported a Rust build failure on riscv/core22 due to a rustup error but later confirmed it was a temporary fluke that did not recur. The issue remains closed pending re-opening if the problem returns. | |
| qwen/qwen3.6-35b-a3b | — | — | Closed as a transient fluke. The author confirmed the rustup error on riscv/core22 did not recur after further testing and will re-open if it happens again. No code changes were applied. | |
| qwen/qwen3.6-35b-a3b | — | — | Closed as a transient fluke. The rustup version selection failure on riscv core22 did not recur, and the author will re-open if it returns. No code changes were applied. | |
| qwen3.6-35b-a3b-mtp-q6 | — | — | Closed as a transient fluke. The author reported a Rust build failure on riscv/core22 due to rustup configuration but could not reproduce it after two weeks. No code changes were applied, and the issue was closed pending recurrence. |
Update history
No update history recorded yet.
Related issues
| Issue | Project | State | Summary | Similarity |
|---|---|---|---|---|
| #4163 snap: use rustup on risc-v | snapcraft | merged | Merged #4163 as commit 95e88a1c1, switching RISC-V snap builds to rustup as a temporary workaround until the core22 migration. | |
| #4175 snap: use rustup for risc-v | snapcraft | closed | Closed as an empty duplicate; #4163 had already merged rustup-based RISC-V snap builds in commit 95e88a1c1. |