# BPF SDK path does not exist

When I was in **step 9 of the tutorial named "**[**Solana 101**](https://github.com/figment-networks/learn-web3-dapp)**"**, I was trying to build my first smart contract. But when I use the command as the book says, I got an unexpected error:

```
$ yarn run solana:build:program                                                                                                       
yarn run v1.22.17
$ cargo build-bpf --manifest-path=contracts/solana/program/Cargo.toml --bpf-out-dir=dist/solana/program
BPF SDK: /Users/alice/.local/share/solana/install/releases/stable-a812f4410ee6195a3b78642f49e07dea69759240/solana-release/bin/sdk/bpf
cargo-build-bpf child: rustup toolchain list -v
cargo-build-bpf child: cargo +bpf build --target bpfel-unknown-unknown --release
    Finished release [optimized] target(s) in 0.28s
cargo-build-bpf child: /Users/alice/.local/share/solana/install/releases/stable-a812f4410ee6195a3b78642f49e07dea69759240/solana-release/bin/sdk/bpf/scripts/strip.sh /Users/alice/Codes/Private/learn-web3-dapp/contracts/solana/program/target/bpfel-unknown-unknown/release/helloworld.so /Users/alice/Codes/Private/learn-web3-dapp/dist/solana/program/helloworld.so
Failed to execute /Users/alice/.local/share/solana/install/releases/stable-a812f4410ee6195a3b78642f49e07dea69759240/solana-release/bin/sdk/bpf/scripts/strip.sh: No such file or directory (os error 2)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
```

We all know this is not about `yarn` itself, so I google and google and google...

Most of the solutions are similar, the first solution is [cargo build-bpf fails](https://github.com/solana-labs/solana/issues/21053), after I tried the answer which has the most thumbs-ups, I got another error which means not work:

```shell-session
$ yarn run solana:build:program                                                                              
yarn run v1.22.17
$ cargo build-bpf --manifest-path=contracts/solana/program/Cargo.toml --bpf-out-dir=dist/solana/program
BPF SDK path does not exist: /Users/alice/.local/share/solana/install/active_release/bin/sdk/bpf: No such file or directory (os error 2)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.l
```

After careful comparison, I found my situation may differ from the above question. So I keep searching and I found another question on StackOverflow with the same keyword "[BPF SDK path does not exist](https://stackoverflow.com/questions/70929961/bpf-sdk-path-does-not-exist)". In the solution, it told me to up the version of Rust to date and check the version of  Solana CLI, so I tried the following:

```shell-session
$ rustup update stable                                                                                       
info: syncing channel updates for 'stable-aarch64-apple-darwin'
-- snip --
  stable-aarch64-apple-darwin updated - rustc 1.60.0 (7737e0b5c 2022-04-04) (from rustc 1.59.0 (9d1b2106e 2022-02-23))

info: checking for self-updates

$ sh -c "$(curl -sSfL https://release.solana.com/v1.10.6/install)"
downloading v1.10.6 installer
  ✨ 1.10.6 initialized
```

I updated the Rust and reinstall the Solana CLI with an exact version, and after that, I tried the build command again:

```shell-session
$ yarn run solana:build:program                                                                              
yarn run v1.22.17
$ cargo build-bpf --manifest-path=contracts/solana/program/Cargo.toml --bpf-out-dir=dist/solana/program
BPF SDK: /Users/alice/.local/share/solana/install/releases/1.10.6/solana-release/bin/sdk/bpf
cargo-build-bpf child: rustup toolchain list -v
cargo-build-bpf child: rustup toolchain uninstall bpf
info: uninstalling toolchain 'bpf'
info: toolchain 'bpf' uninstalled
cargo-build-bpf child: rustup toolchain link bpf /Users/alice/.local/share/solana/install/releases/1.10.6/solana-release/bin/sdk/bpf/dependencies/bpf-tools/rust
cargo-build-bpf child: cargo +bpf build --target bpfel-unknown-unknown --release
-- snip compile log --
+ rustup toolchain uninstall bpf
info: uninstalling toolchain 'bpf'
info: toolchain 'bpf' uninstalled
+ set -e
+ rustup toolchain link bpf bpf-tools/rust
+ exit 0
cargo-build-bpf child: /Users/alice/.local/share/solana/install/releases/1.10.6/solana-release/bin/sdk/bpf/dependencies/bpf-tools/llvm/bin/llvm-readelf --dyn-symbols /Users/alice/Codes/Private/learn-web3-dapp/dist/solana/program/helloworld.so

To deploy this program:
  $ solana program deploy /Users/alice/Codes/Private/learn-web3-dapp/dist/solana/program/helloworld.so
The program address will default to this keypair (override with --program-id):
  /Users/alice/Codes/Private/learn-web3-dapp/dist/solana/program/helloworld-keypair.json
✨  Done in 23.40s.
```

Wow! It works! I think maybe the previous version of Solana CLI I installed is somehow broken or not suitable for the Rust version. I'm relieved to finally be able to compile the program.