Nondeterministic resolution (?) causing dependency to flap in Cargo.lock about cargo HOT 3 OPEN

(This is derive-deftly ticket 82)

from cargo.

This mentions 1.79.0-beta.3. I've reproduced this on 1.64

from cargo.

So the reproduction step has us cherry pick a20d8994f74e091a0df864211e087e5ed5f15615

diff --git c/Cargo.toml w/Cargo.toml
index 80f8e24..48d3569 100644
--- c/Cargo.toml
+++ w/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "derive-deftly"
-version = "0.11.0"
+version = "0.10.666"
 edition = "2021"
 license="MIT"
 authors=["Ian Jackson <[email protected]>",

• This is why changes in version are expected
• There are registry dependencies on derive-deftly 0.11.0, so that is why the disambiguation changes are there

On the baseline commit:

$ cargo tree -i [email protected]
heck v0.4.1
└── strum_macros v0.26.2 (proc-macro)
    └── strum v0.26.2
        └── derive-deftly-macros v0.11.0 (proc-macro) (/home/epage/src/personal dump/rust-derive-deftly/macros)
            └── derive-deftly v0.11.0 (/home/epage/src/personal/dump/rust-derive-deftly)
$ cargo tree -i [email protected]
heck v0.5.0
├── derive-deftly v0.11.0 (/home/epage/src/personal/dump/rust-derive-deftly)
└── derive-deftly-macros v0.11.0 (proc-macro) (/home/epage/src/personal/dump/rust-derive-deftly/macros)
    └── derive-deftly v0.11.0 (/home/epage/src/personal/dump/rust-derive-deftly)

• strum_macros depends on heck = "0.4.1"
• both derive-deftly and derive-deftly-macros depends on heck = ">=0.4, <0.6"
  • The registry version has the same version requirement

However, if I run

$ cargo generate-lockfile

then the version of heck doesn't change.

So overall, I'm not finding anything out of the ordinary than wide version ranges.
My general assumption has always been that we pick the highest version for each version range. However, what is likely happening here is that we are resolving derive-deflty freshly and seeing an existing locked resolve of heck and picking that.

We have #13535 for tweaking the logic which might make this more consistent.

from cargo.