filter_iter example fails to compile on Windows because it depends on bdk_testenv

[NaitikVerma6776]

Context

Discovered while using BDK as a new developer: after the bdk_bitcoind_rpc library crate compiled, I followed the in-tree example instructions to run the only official example.

Reproduction

On Windows, from a checkout of this repository:

cargo build -p bdk_bitcoind_rpc
cargo build -p bdk_bitcoind_rpc --example filter_iter

The first command succeeds. The second fails.

crates/bitcoind_rpc/examples/README.md documents the same example as:

cargo run -p bdk_bitcoind_rpc --example filter_iter

Expected behavior

The documented example should compile on a host where bdk_bitcoind_rpc itself compiles. Runtime still needs a local bitcoind (RPC_URL / RPC_COOKIE); that is already documented. Compile should not require the Unix-only test harness.

Actual behavior

Building the example pulls in the bdk_testenv dev-dependency and fails in electrsd 0.38.1's build.rs:

error[E0433]: cannot find `unix` in `os`
  --> electrsd-0.38.1\build.rs:14:18
   |
14 |     use std::os::unix::fs::PermissionsExt;

error[E0599]: no associated function or constant named `from_mode` found for struct `Permissions`
  --> electrsd-0.38.1\build.rs:78:39

The example does not use TestEnv. It only imports anyhow from bdk_testenv:

use anyhow::Context;
use bdk_testenv::anyhow;

Because Cargo examples may use the package's dev-dependencies, that import is enough to compile electrsd.

Environment

• BDK commit: 0790f0400b108974b538e44d6498dc6fe1157548
• Crate: bdk_bitcoind_rpc 0.22.0 (filter_iter example)
• OS: Windows 10 (10.0.26200), x86_64-pc-windows-msvc
• Rust: rustc 1.97.1 (8bab26f4f 2026-07-14)

Which backend(s) are relevant (if any)?

• Bitcoin Core RPC

Is this blocking production use?

• No

Additional context

bdk_testenv depending on electrsd is reasonable for integration tests. It is surprising for this example, because the example talks to an already-running Signet bitcoind and does not start a regtest node.

This is a build/developer-experience issue, not a runtime bug in FilterIter.

Related but different:

• Test CLI examples using a regtest node in CI #1618 / PR test(bitcoind_rpc): add regtest coverage for filter_iter example #2329 — CI coverage for the example path on Ubuntu
• Improve safety of FilterIter #2268 — FilterIter safety

[NaitikVerma6776]

HIi @notmandatory , I’m Naitik! I’m a CSE student and an open-source enthusiast. I’ve been contributing to different open-source projects for a while and recently started getting more interested in the Bitcoin ecosystem.

I’m familiar with Rust and wanted to get more hands-on with Bitcoin development, which is what brought me to BDK. Instead of just going through the code, I recently tried using BDK from a real developer/user perspective and built a small Signet app using bdk_chain, bdk_esplora and bdk_file_store.

While going through the actual workflow, I also ran into a small Windows build issue with the filter_iter example and opened #2338 with the reproduction details.

I’m still getting familiar with BDK and the Bitcoin ecosystem, but I’d really like to contribute here and learn from the community. Looking forward to getting involved!