Killing a gptel buffer while it's typing blocks Emacs until the response is complete

[igmacs]

Please update gptel first -- errors are often fixed by the time they're reported.

• I have updated gptel to the latest commit and tested that the issue still exists

Bug Description

If you kill the gptel buffer while it's typing, you get constant errors for a while, and can't do anything with Emacs until the errors finish. I guess they occur while the model is still answering, and finish when the answer is complete.

The errors are the following, in a loop:

error in process filter: gptel-curl--stream-filter: Wrong type argument: stringp, nil
error in process filter: Wrong type argument: stringp, nil

I know the proper way to abort a gptel query is with gptel-abort, but if you do a prompt and see the model is hallucinating the answer or not giving you the result you expected, a natural reaction could be to just kill the buffer, or at least I did that.

Running the following in the gptel buffer fixes it: (add-hook 'kill-buffer-hook (lambda () (gptel-abort (current-buffer))) 0 t)

Backend

Other (please specify in Additional Context)

Steps to Reproduce

1. M-x gptel
2. Query something like this: Please output the numbers 1 to 500, each in a separate line
3. As soon as it starts writing the output, do M-x kill-buffer

Additional Context

I doubt this is dependent of particular versions or backends, but my Emacs version is 30.2, my curl version 8.6.0, I'm using Copilot, and of course I pulled the latest gptel changes before trying to reproduce again.

Backtrace

If you toggle debug on error, the backtrace that can appear seems to be a little bit non-determistic, I provide here the two versions I got:


Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  gptel-curl--stream-insert-response("\n" (:uuid "af31290e5fb845593919dee23fb66d94" :transformer #f(compiled-function (str) #<bytecode 0x19399de8589fb138>) :callback gptel-curl--stream-insert-response :history (WAIT INIT) :data (:model "gpt-4.1" :messages [(:role "system" :content "You are a large language model living in Emacs and a helpful assistant. Respond concisely.") (:role "user" :content "* Please output the numbers 1 to 500, each in a separate line")] :stream t :stream_options (:include_usage t)) :buffer #<killed buffer> :position #<marker in no buffer> :transforms (gptel--transform-apply-preset gptel--transform-add-context) :stream t :backend #s(gptel--gh :name "Copilot" :host "api.githubcopilot.com" :header #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_57> :protocol "https" :stream t :endpoint "/chat/completions" :key nil :models (gpt-4.1 gpt-4o gpt-5-mini gpt-5.1 gpt-5.1-codex gpt-5.1-codex-max gpt-5.1-codex-mini gpt-5.2 gpt-5.2-codex gpt-5.3-codex gpt-5.4 gpt-5.4-mini gpt-5.5 claude-haiku-4.5 claude-opus-4.5 claude-opus-4.6 claude-opus-4.7 claude-sonnet-4 claude-sonnet-4.5 claude-sonnet-4.6 gemini-2.5-pro gemini-3-flash-preview gemini-3-pro-preview gemini-3.1-pro-preview gemini-3.5-flash grok-code-fast-1) :url #f(compiled-function (info) #<bytecode -0x1b1119c8277c3e5c>) :request-params nil :curl-args nil :coding-system nil :token (:agent_mode_auto_approval t :annotations_enabled t :azure_only :json-false :blackbird_clientside_indexing :json-false :blackbird_external_indexing t :chat_enabled t :chat_jetbrains_enabled t :code_quote_enabled t :code_review_enabled t :codesearch t :copilotignore_enabled :json-false :endpoints (:api "https://api.individual.githubcopilot.com" :origin-tracker "https://origin-tracker.individual.githubcopilot.com" :proxy "https://proxy.individual.githubcopilot.com" :telemetry "https://telemetry.individual.githubcopilot.com") :expires_at 1781084339 :iat 1781082539 :individual t :limited_user_quotas :null :limited_user_reset_date :null :public_suggestions "disabled" :refresh_in 1500 :sku "monthly_subscriber_quota" :telemetry "disabled" :token "tid=cc7391a1f6e380788be9f639b036af5b;exp=1781084339;iat=1781082539;sku=monthly_subscriber_quota;proxy-ep=proxy.individual.githubcopilot.com;st=dotcom;chat=1;cit=1;malfil=1;editor_preview_features=1;agent_mode=1;agent_mode_auto_approval=1;mcp=1;blackbird_external_indexing=1;client_byok=0;ccr=1;ip=139.47.35.71;asn=AS15704:b21669c2ec53403b6e031bfaf52ccb7d598ed98f712a22a973ef6868800545b2" :tracking_id "cc7391a1f6e380788be9f639b036af5b" :xcode t :xcode_chat :json-false) :github-token "ghu_kvqymHP5FsOJSnBYo72h0BFGX1ccKE41ZTTU" :sessionid nil :machineid "cdfe0dc3adc72d5d8d4a4d2871e66fbf16c9b33dbbfb821c377be240bef5aedbd" :responses-backend #s(gptel-openai-responses :name "Copilot" :host "api.githubcopilot.com" :header #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_57> :protocol "https" :stream t :endpoint "/v1/responses" :key nil :models nil :url #f(compiled-function (info) #<bytecode -0x1b1119c8277c3e5c>) :request-params nil :curl-args nil :coding-system nil)) :model gpt-4.1 :include-reasoning ignore :gh-initiator "agent" :http-status "200" :status "HTTP/2 200" :reasoning-block done :tracking-marker #<marker (moves after insertion) in no buffer>))
  gptel-curl--stream-filter(#<process gptel-curl> "data: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"\\n\"}}],\"created\":1781082541,\"id\":\"chatcmpl-Dp9DhCzSGDlOcQ7Us6Yv6HCF84D6P\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\n")



Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  gptel-curl--stream-insert-response("\n30\n31\n32\n33\n34\n35\n36\n37\n38\n39\n40\n41\n42\n43\n44\n45" (:uuid "f4ee29272ae45ba5302e561cb70f9484" :transformer #f(compiled-function (str) #<bytecode 0x19730bd0b11fb138>) :callback gptel-curl--stream-insert-response :history (WAIT INIT) :data (:model "gpt-4.1" :messages [(:role "system" :content "You are a large language model living in Emacs and a helpful assistant. Respond concisely.") (:role "user" :content "* Please output the numbers 1 to 500, each in a separate line")] :stream t :stream_options (:include_usage t)) :buffer #<killed buffer> :position #<marker in no buffer> :transforms (gptel--transform-apply-preset gptel--transform-add-context) :stream t :backend #s(gptel--gh :name "Copilot" :host "api.githubcopilot.com" :header #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_57> :protocol "https" :stream t :endpoint "/chat/completions" :key nil :models (gpt-4.1 gpt-4o gpt-5-mini gpt-5.1 gpt-5.1-codex gpt-5.1-codex-max gpt-5.1-codex-mini gpt-5.2 gpt-5.2-codex gpt-5.3-codex gpt-5.4 gpt-5.4-mini gpt-5.5 claude-haiku-4.5 claude-opus-4.5 claude-opus-4.6 claude-opus-4.7 claude-sonnet-4 claude-sonnet-4.5 claude-sonnet-4.6 gemini-2.5-pro gemini-3-flash-preview gemini-3-pro-preview gemini-3.1-pro-preview gemini-3.5-flash grok-code-fast-1) :url #f(compiled-function (info) #<bytecode -0x1b1119c8277c3e5c>) :request-params nil :curl-args nil :coding-system nil :token (:agent_mode_auto_approval t :annotations_enabled t :azure_only :json-false :blackbird_clientside_indexing :json-false :blackbird_external_indexing t :chat_enabled t :chat_jetbrains_enabled t :code_quote_enabled t :code_review_enabled t :codesearch t :copilotignore_enabled :json-false :endpoints (:api "https://api.individual.githubcopilot.com" :origin-tracker "https://origin-tracker.individual.githubcopilot.com" :proxy "https://proxy.individual.githubcopilot.com" :telemetry "https://telemetry.individual.githubcopilot.com") :expires_at 1781084339 :iat 1781082539 :individual t :limited_user_quotas :null :limited_user_reset_date :null :public_suggestions "disabled" :refresh_in 1500 :sku "monthly_subscriber_quota" :telemetry "disabled" :token "tid=cc7391a1f6e380788be9f639b036af5b;exp=1781084339;iat=1781082539;sku=monthly_subscriber_quota;proxy-ep=proxy.individual.githubcopilot.com;st=dotcom;chat=1;cit=1;malfil=1;editor_preview_features=1;agent_mode=1;agent_mode_auto_approval=1;mcp=1;blackbird_external_indexing=1;client_byok=0;ccr=1;ip=139.47.35.71;asn=AS15704:b21669c2ec53403b6e031bfaf52ccb7d598ed98f712a22a973ef6868800545b2" :tracking_id "cc7391a1f6e380788be9f639b036af5b" :xcode t :xcode_chat :json-false) :github-token "ghu_kvqymHP5FsOJSnBYo72h0BFGX1ccKE41ZTTU" :sessionid nil :machineid "cdfe0dc3adc72d5d8d4a4d2871e66fbf16c9b33dbbfb821c377be240bef5aedbd" :responses-backend #s(gptel-openai-responses :name "Copilot" :host "api.githubcopilot.com" :header #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_57> :protocol "https" :stream t :endpoint "/v1/responses" :key nil :models nil :url #f(compiled-function (info) #<bytecode -0x1b1119c8277c3e5c>) :request-params nil :curl-args nil :coding-system nil)) :model gpt-4.1 :include-reasoning ignore :gh-initiator "agent" :http-status "200" :status "HTTP/2 200" :reasoning-block done :tracking-marker #<marker (moves after insertion) in no buffer>))
  gptel-curl--stream-filter(#<process gptel-curl<3>> "data: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"\\n\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"30\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"\\n\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"31\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"\\n\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"32\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"\\n\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"33\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"severity\":\"safe\"},\"self_harm\":{\"filtered\":false,\"severity\":\"safe\"},\"sexual\":{\"filtered\":false,\"severity\":\"safe\"},\"violence\":{\"filtered\":false,\"severity\":\"safe\"}},\"delta\":{\"content\":\"\\n\"}}],\"created\":1781082765,\"id\":\"chatcmpl-Dp9HJm4KXjmUiQRRBUFYfWlfjLSeA\",\"model\":\"gpt-4.1-2025-04-14\",\"system_fingerprint\":\"fp_dc49d4fcba\"}\n\ndata: {\"choices\":[{\"index\":0,\"content_filter_results\":{\"hate\":{\"filtered\":false,\"sev...")


Also, when getting them, I realized that Emacs it's not exactly blocked, but I guess something different. If debug on error is not enabled, for me it looks like it's blocked. But if it's enabled, the backtrace buffer is selected, and there I can move the point, although I can't switch buffers either, so the result is mostly the same.

Log Information

[djr7C4]

Try my PR #1422. It's been working well for me but if you find any cases that aren't covered let me know.