Enabling both envars produces fuller backtrace, as below. On Sun, 22 Feb 2026, Dr Bean via Cygwin wrote:
> I'm trying to build tooi, a python mastodon TUI > (https://codeberg.org/ihabunek/tooi), which depends on > pydantic, a python-rust data validation module. > Building with python-3.12, in a venv virtual > environment, invoking `pip3 install .`, > pydantic fails with the message, > Building wheel for pydantic-core (pyproject.toml) ... error > error: subprocess-exited-with-error > × Building wheel for pydantic-core (pyproject.toml) did not run > successfully. > │ exit code: 1 > ╰─> [22 lines of output] > Running `maturin pep517 build-wheel -i > /home/drbean/dot/browser/tooi/.venv.312/bin/python3 --compatibility off` > 🍹 Building a mixed python/rust project > 🔗 Found pyo3 bindings > 🐍 Found CPython 3.12 at > /home/drbean/dot/browser/tooi/.venv.312/bin/python3 > 📡 Using build options bindings from pyproject.toml > Compiling proc-macro2 v1.0.86 > Compiling unicode-ident v1.0.12 > Compiling target-lexicon v0.13.2 > error: failed to run custom build command for `target-lexicon v0.13.2` > Caused by: > process didn't exit successfully: > `/tmp/pip-install-jvwnp9e1/pydantic-core_f4b932677649467ab031f90bc26a5065/target/release/build/target-lexicon-a0d8869a1d22c23b/build-script-build` > (exit status: 101) > --- stderr > thread 'main' (1) panicked at > /home/drbean/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/target-lexicon-0.13.2/build.rs:52:54: > Invalid target name: 'x86_64-pc-cygwin' > note: run with `RUST_BACKTRACE=1` environment variable to display a > backtrace > warning: build failed, waiting for other jobs to finish... > 💥 maturin failed > Caused by: Failed to build a native library through cargo > Caused by: Cargo build finished with "exit status: 101": `env -u > CARGO PYO3_BUILD_EXTENSION_MODULE="1" > PYO3_ENVIRONMENT_SIGNATURE="cpython-3.12-64bit" > PYO3_PYTHON="/home/drbean/dot/browser/tooi/.venv.312/bin/python3" > PYTHON_SYS_EXECUTABLE="/home/drbean/dot/browser/tooi/.venv.312/bin/python3" > "cargo" "rustc" "--profile" "release" "--message-format" > "json-render-diagnostics" "--manifest-path" > "/tmp/pip-install-jvwnp9e1/pydantic-core_f4b932677649467ab031f90bc26a5065/Cargo.toml" > "--lib" "--crate-type" "cdylib"` > Error: command ['maturin', 'pep517', 'build-wheel', '-i', > '/home/drbean/dot/browser/tooi/.venv.312/bin/python3', '--compatibility', > 'off'] returned non-zero exit status 1 > [end of output] > note: This error originates from a subprocess, and is likely not a problem > with pip. > ERROR: Failed building wheel for pydantic-core > Successfully built toot-tooi > Failed to build pydantic-core > Running with RUST_BACKTRACE=1 and then RUST_BACKTRACE=full, produces > the same output but in addition the backtrace, > --->% > error: failed to run custom build command for `target-lexicon v0.13.2` > note: To improve backtraces for build dependencies, set the > CARGO_PROFILE_RELEASE_BUILD_OVERRIDE_DEBUG=true environment variable to > enable debug information generation. > Caused by: > process didn't exit successfully: > `/tmp/pip-install-i6xwee_g/pydantic-core_d54b807af2e64234b3895bffc7166967/target/release/build/target-lexicon-a0d8869a1d22c23b/build-script-build` > (exit status: 101) > --- stderr > thread 'main' (1) panicked at > /home/drbean/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/target-lexicon-0.13.2/build.rs:52:54: > Invalid target name: 'x86_64-pc-cygwin' > stack backtrace: > 0: 0x10045e9b0 - <unknown> > 1: 0x10048d1aa - <unknown> > 2: 0x1004186ff - <unknown> > 3: 0x10042a0e5 - <unknown> > 4: 0x100431ba2 - <unknown> > 5: 0x100431a1a - <unknown> > 6: 0x100432367 - <unknown> > 7: 0x100432132 - <unknown> > 8: 0x10042a21f - <unknown> > 9: 0x10040fece - <unknown> > 10: 0x10049db01 - <unknown> > 11: 0x1004091bd - <unknown> > 12: 0x10040ae1c - <unknown> > 13: 0x100408f9d - <unknown> > 14: 0x1004099b6 - <unknown> > 15: 0x1004094b9 - <unknown> > 16: 0x100401bac - <unknown> > 17: 0x10041c045 - <unknown> > 18: 0x100401b97 - <unknown> > 19: 0x10040d80f - <unknown> > 20: 0x7ffc3dbf80f3 - <unknown> > 21: 0x7ffc3dbf5cd5 - <unknown> > 22: 0x7ffc3dbf5d8b - <unknown> > 23: 0x0 - <unknown> > warning: build failed, waiting for other jobs to finish... > ------>% > Running with the advised > CARGO_PROFILE_RELEASE_BUILD_OVERRIDE_DEBUG=true envar > produces the same output as with no envars. > Reading from a "Platform" dropdown on a target-lexicon > doc page, https://docs.rs/crate/target-lexicon/latest > the supported platforms appear to be > aarch64-apple-darwin > aarch64-unknown-linux-gnu > i686-pc-windows-msvc > x86_64-pc-windows-msvc > x86_64-unknown-linux-gnu > That is, no x86_64-pc-cygwin Enabling both RUST_BACKTRACE=full and CARGO_PROFILE_RELEASE_BUILD_OVERRIDE_DEBUG=true produces more information: × Building wheel for pydantic-core (pyproject.toml) did not run successfully. │ exit code: 1 ╰─> [91 lines of output] Running `maturin pep517 build-wheel -i /home/drbean/dot/browser/tooi/.venv.312/bin/python3 --compatibility off` 🍹 Building a mixed python/rust project 🔗 Found pyo3 bindings 🐍 Found CPython 3.12 at /home/drbean/dot/browser/tooi/.venv.312/bin/python3 📡 Using build options bindings from pyproject.toml Compiling proc-macro2 v1.0.86 Compiling unicode-ident v1.0.12 Compiling target-lexicon v0.13.2 error: failed to run custom build command for `target-lexicon v0.13.2` Caused by: process didn't exit successfully: `/tmp/pip-install-s56o7awx/pydantic-core_db6fcc382f8942f1b53e915621dc0eb1/target/release/build/target-lexicon-64e748e5367b5657/build-script-build` (exit status: 101) --- stderr thread 'main' (1) panicked at /home/drbean/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/target-lexicon-0.13.2/build.rs:52:54: Invalid target name: 'x86_64-pc-cygwin' stack backtrace: 0: 0x100460b20 - std::backtrace_rs::backtrace::libunwind::trace::hb646b3818c959e30 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9 1: 0x100460b20 - std::backtrace_rs::backtrace::trace_unsynchronized::hccaef05b188d129d at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14 2: 0x100460b20 - std::sys::backtrace::_print_fmt::h125f99c616e9f9a8 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/sys/backtrace.rs:66:9 3: 0x100460b20 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::ha6ddd3ae47888e14 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/sys/backtrace.rs:39:26 4: 0x10048f31a - core::fmt::rt::Argument::fmt::h00686ef01f35f425 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/core/src/fmt/rt.rs:173:76 5: 0x10048f31a - core::fmt::write::hafb6881693bf3ac2 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/core/src/fmt/mod.rs:1468:25 6: 0x10041a86f - std::io::default_write_fmt::h4dab8dfbed8868d4 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/io/mod.rs:639:11 7: 0x10041a86f - std::io::Write::write_fmt::h6edf97c3b63c3bce at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/io/mod.rs:1954:13 8: 0x10042c255 - std::sys::backtrace::BacktraceLock::print::hd2c616b84c76485c at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/sys/backtrace.rs:42:9 9: 0x100433d12 - std::panicking::default_hook::{{closure}}::h6da411585cd73d3b at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:301:27 10: 0x100433b8a - std::panicking::default_hook::h8cc9d3cc33951cab at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:328:9 11: 0x1004344d7 - std::panicking::panic_with_hook::h4312c31a5a302915 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:834:13 12: 0x1004342a2 - std::panicking::panic_handler::{{closure}}::hd9bcf2a0d94c90cb at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:707:13 13: 0x10042c38f - std::sys::backtrace::__rust_end_short_backtrace::hf2f69349f5fedde2 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/sys/backtrace.rs:174:18 14: 0x10041203e - __rustc[bb0b2f28308e8f2c]::rust_begin_unwind at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:698:5 15: 0x10049fc71 - core::panicking::panic_fmt::h4fdf6c90c527357e at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/core/src/panicking.rs:75:14 16: 0x100402375 - build_script_build::main::{{closure}}::h9b09661ee805f8eb at /home/drbean/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/target-lexicon-0.13.2/build.rs:52:54 17: 0x10040bdae - core::result::Result<T,E>::unwrap_or_else::hde682de2de6c2c40 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/core/src/result.rs:1615:23 18: 0x10040213d - build_script_build::main::h3471bd3a69afb0f6 at /home/drbean/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/target-lexicon-0.13.2/build.rs:52:35 19: 0x10040a51b - core::ops::function::FnOnce::call_once::h0752857881febfc5 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/core/src/ops/function.rs:250:5 20: 0x100409f2e - std::sys::backtrace::__rust_begin_short_backtrace::hc45b17075d48ad69 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/sys/backtrace.rs:158:18 21: 0x100402771 - std::rt::lang_start::{{closure}}::hc389f9dae62d10bf at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/rt.rs:206:18 22: 0x10041e1b5 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::hc60b0456de58364d at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/core/src/ops/function.rs:287:21 23: 0x10041e1b5 - std::panicking::catch_unwind::do_call::h2e5898e688b1a50b at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:590:40 24: 0x10041e1b5 - std::panicking::catch_unwind::h7f62609155fe9d0e at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:553:19 25: 0x10041e1b5 - std::panic::catch_unwind::h0ba95c81ca504784 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panic.rs:359:14 26: 0x10041e1b5 - std::rt::lang_start_internal::{{closure}}::h0c3db5bbfb345efc at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/rt.rs:175:24 27: 0x10041e1b5 - std::panicking::catch_unwind::do_call::h63c21c83bfb6e719 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:590:40 28: 0x10041e1b5 - std::panicking::catch_unwind::h0d97b5c5b15613b0 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panicking.rs:553:19 29: 0x10041e1b5 - std::panic::catch_unwind::h8fbdd35aeccb7f71 at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/panic.rs:359:14 30: 0x10041e1b5 - std::rt::lang_start_internal::h9c9e175168bee11c at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/rt.rs:171:5 31: 0x10040275a - std::rt::lang_start::hd92f0fe6ad35a7be at /cygdrive/d/a/scallywag/rust/rust-1.91.0-1.x86_64/src/rustc-1.91.0-src/library/std/src/rt.rs:205:5 32: 0x1004095ef - main 33: 0x7ffb7d4980f3 - <unknown> 34: 0x7ffb7d495cd5 - <unknown> 35: 0x7ffb7d495d8b - <unknown> 36: 0x0 - <unknown> warning: build failed, waiting for other jobs to finish... 💥 maturin failed Caused by: Failed to build a native library through cargo Caused by: Cargo build finished with "exit status: 101": `env -u CARGO PYO3_BUILD_EXTENSION_MODULE="1" PYO3_ENVIRONMENT_SIGNATURE="cpython-3.12-64bit" PYO3_PYTHON="/home/drbean/dot/browser/tooi/.venv.312/bin/python3" PYTHON_SYS_EXECUTABLE="/home/drbean/dot/browser/tooi/.venv.312/bin/python3" "cargo" "rustc" "--profile" "release" "--message-format" "json-render-diagnostics" "--manifest-path" "/tmp/pip-install-s56o7awx/pydantic-core_db6fcc382f8942f1b53e915621dc0eb1/Cargo.toml" "--lib" "--crate-type" "cdylib"` Error: command ['maturin', 'pep517', 'build-wheel', '-i', '/home/drbean/dot/browser/tooi/.venv.312/bin/python3', '--compatibility', 'off'] returned non-zero exit status 1 [end of output] -- Greg "Dr Bean" Matheson Academic politics is so bitter because the stakes http://drbean.sdf.org are so small. 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