Do not build a cdylib for lance-arrow - #75
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The vendored `lance-arrow` crate declares `crate-type = ["cdylib", "rlib"]`. ClickHouse only consumes the `rlib`, but Cargo still links the shared library, and for a shared library `rustc` appends its default linker libraries (`-lgcc_s`, `-lutil`, ...). The ClickHouse sysroot does not carry those, so the link fails with `ld.lld: error: unable to find library -lgcc_s`. Drop the unused `cdylib` crate type.
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The Lance crates were never actually compiled in CI: every run stopped at `Checkout Submodules`, because `contrib/rust_vendor` pointed at a commit that only existed in a fork. With the submodule pointer fixed, three real build failures surface. 1. `lance-encoding`, `lance-index` and friends generate Rust code from `.proto` files with `prost-build`, which needs a `protoc` binary and the well-known type definitions. Point `PROTOC` at the `protoc` ClickHouse builds from `contrib/google-protobuf` and `PROTOC_INCLUDE` at its `src` directory, instead of silently depending on a host installation. When cross-compiling, `protoc` comes from the nested native build, the same way `protobuf_generate` uses it. `ENABLE_LANCE` now requires Protobuf. 2. The vendored `lance-arrow` crate declares `crate-type = ["cdylib", "rlib"]`. Only the `rlib` is consumed, but Cargo still links the shared library, and for a shared library `rustc` appends default linker libraries (`-lgcc_s`, `-lutil`) that the ClickHouse sysroot does not carry. Fixed in `rust_vendor` (ClickHouse/rust_vendor#75) and picked up here via the submodule pointer. 3. Four crates newly vendored for Lance declare the license `Zlib OR MIT OR Apache-2.0`, an ordering `list-licenses.sh` did not know, so `StorageSystemLicenses.generated.cpp` could not be generated and CMake configuration failed.
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🕵 The vendored
lance-arrowcrate declarescrate-type = ["cdylib", "rlib"]. ClickHouse only consumes therlib, but Cargo still links the shared library, and for a shared libraryrustcappends its default linker libraries (-lgcc_s,-lutil, ...). The ClickHouse sysroot does not carry those, so every build of the Lance adapter fails with:This drops the unused
cdylibcrate type (and updates.cargo-checksum.jsonaccordingly). With it,ninja _cargo-build__ch_rust_lanceand the fullclickhousebinary build.Needed by ClickHouse/ClickHouse#110548
Related: #71