Add repr(c) for SplitStream header structs#266
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cgwalters merged 1 commit intocomposefs:mainfrom Mar 17, 2026
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While trying out composefs#263 locally, I found that Rust is rearranging the SplitStreamHeader struct's fields to the following ``` [32, 0, 0, 0, 0, 0, 0, 0, 112, 0, 0, 0, 0, 0, 0, 0, 0, 0, 83, 112, 108, 105, 116, 83, 116, 114, 101, 97, 109, 0, 2, 12] ``` The first two U64 are the start and end of the field `info` when `info` is the last field in the struct; then comes the flags which is the third field... We probably don't want this undeterministic behaviour, which might also change from arch to arch Signed-off-by: Pragyan Poudyal <pragyanpoudyal41999@gmail.com>
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This has the very unfortunate effect of breaking any previously created repos |
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Yes...though... per https://docs.rs/zerocopy/latest/zerocopy/derive.IntoBytes.html while we clearly should have been using |
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OK I think #263 is also format breaking (will verify). My 2c is let's change bootc to detect this case and fall back to re-fetching the image? |
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I also have a pending PR for #181 so basically - detect meta.json and if not fall back to re-fetch? |
cgwalters
approved these changes
Mar 17, 2026
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While trying out #263 locally, I found that Rust is rearranging the SplitStreamHeader struct's fields to the following
The first two U64 are the start and end of the field
infowheninfois the last field in the struct; then comes the flags which is the third field...We probably don't want this undeterministic behaviour, which might also change from arch to arch