curl Exit Code 35 in CI: SSL/TLS Handshake Failure
curl exit code 35 means the SSL/TLS handshake failed before any data could be exchanged.
A step exiting 35 from curl connected at the TCP level but could not negotiate a secure session.
What it means
Exit 35 is curl's CURLE_SSL_CONNECT_ERROR. The TLS handshake failed - a protocol version mismatch, an unsupported cipher, or an interrupted negotiation.
Common causes
- The server requires a TLS version the client disabled (or vice versa).
- A cipher/curve mismatch.
- A MITM proxy interfering with the handshake.
How to fix it
Run with -v to see the handshake detail, align TLS versions/ciphers, and update the CA bundle or curl/OpenSSL version. A momentarily flaky handshake can clear on retry.
Reading exit codes in CI
- A shell reports
128 + Nwhen a process is terminated by signal N: 137 is SIGKILL (usually the out-of-memory killer), 143 is SIGTERM, 130 is SIGINT. - Exit code 137 in a container almost always means the kernel killed it for memory. Nothing in the application log will explain it.
- A pipeline reports the exit status of its LAST command unless
pipefailis set, which is how a failing command piped toteeproduces a green build. - Some tools use non-zero codes for non-failure outcomes. Check the tool documentation before treating any non-zero code as an error.
Frequently asked questions
curl Exit Code 35 in CI: SSL/TLS Handshake Failure?
A step exiting 35 from curl connected at the TCP level but could not negotiate a secure session.
What it means?
Exit 35 is curl's CURLE_SSL_CONNECT_ERROR. The TLS handshake failed - a protocol version mismatch, an unsupported cipher, or an interrupted negotiation.
How to fix it?
Run with -v to see the handshake detail, align TLS versions/ciphers, and update the CA bundle or curl/OpenSSL version. A momentarily flaky handshake can clear on retry.
Related guides
curl Exit Code 28 in CI: Operation Timed Outcurl exit code 28 means the operation timed out - connect or transfer exceeded the timeout.
curl Exit Code 56 in CI: Failure Receiving Network Datacurl exit code 56 means a failure receiving network data - the connection was reset or dropped mid-transfer.
CI Exit Codes: What Each One Actually Tells YouExit codes you see in CI logs and what each indicates, including why 137 is never an application error and