ed-mcp: skip the child-process transport on tvOS
tvOS has no exec, so rmcp's transport-child-process feature pulls in nix, which does not compile there. Move that feature into a cfg(not(target_os = "tvos")) dependency and gate the stdio transport arm the same way. On tvOS a stdio MCP server now fails with a plain message instead of the crate refusing to build. cargo +nightly rustc -Z build-std -p ed-mcp --target aarch64-apple-tvos now compiles; the HTTP transport and the rest of the workspace are unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Co-Authored-By: siGit Code v1.6.9 <noreply@sigit.si>
Seto Elkahfi committed
Oct 14, 2026 at 22:20 UTC
8e12a74e7029ecde0bdb8f74dde455a499d10fbf
2 files changed
+19
-2
crates/ed-mcp/Cargo.toml
+7
-1
@@ -16,7 +16,7 @@ agent-client-protocol = { workspace = true, optional = true }
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ed-agent = { workspace = true, optional = true }
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async-trait = { workspace = true, optional = true }
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http = "1"
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-rmcp = { workspace = true, features = ["client", "transport-child-process", "transport-streamable-http-client-reqwest", "reqwest"] }
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+rmcp = { workspace = true, features = ["client", "transport-streamable-http-client-reqwest", "reqwest"] }
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tokio = { workspace = true, features = ["sync", "time", "process", "macros", "io-std", "io-util", "rt"] }
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tokio-util.workspace = true
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futures.workspace = true
@@ -24,6 +24,12 @@ serde_json.workspace = true
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anyhow.workspace = true
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tracing.workspace = true
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+# Spawning an MCP server as a child process needs `exec`, which Apple hides on tvOS (`libc`
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+# has no `execv` there, so `nix` under `process-wrap` doesn't compile). The stdio transport
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+# is everywhere else.
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+[target.'cfg(not(target_os = "tvos"))'.dependencies]
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+rmcp = { workspace = true, features = ["transport-child-process"] }
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+
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[features]
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# Map ACP `session/new` MCP server lists (`McpToolset::connect`, `ServerSpec::from_acp`).
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# Pulls in `agent-client-protocol`; `ed-acp` enables it.
crates/ed-mcp/src/lib.rs
+12
-1
@@ -34,8 +34,10 @@ use rmcp::model::{
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Implementation, ProgressNotificationParam, Request, ServerResult, Tool,
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};
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use rmcp::service::{NotificationContext, PeerRequestOptions, RequestContext, RunningService};
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+use rmcp::transport::StreamableHttpClientTransport;
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+#[cfg(not(target_os = "tvos"))]
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+use rmcp::transport::TokioChildProcess;
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use rmcp::transport::streamable_http_client::StreamableHttpClientTransportConfig;
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-use rmcp::transport::{StreamableHttpClientTransport, TokioChildProcess};
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use rmcp::{ClientHandler, ErrorData as McpError, RoleClient, ServiceExt};
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use serde_json::{Map, Value, json};
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use tokio::sync::Mutex;
@@ -332,6 +334,7 @@ impl Connection {
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elicitation,
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};
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let handshake = match &spec.transport {
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+ #[cfg(not(target_os = "tvos"))]
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Transport::Stdio { command, args, env } => {
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let mut cmd = tokio::process::Command::new(command);
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cmd.args(args).envs(env.iter().map(|(k, v)| (k, v)));
@@ -339,6 +342,14 @@ impl Connection {
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.with_context(|| format!("starting {}", command.display()))?;
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tokio::time::timeout(timeout, handler.serve(transport)).await
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}
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+ // tvOS can't start a process, so there is no stdio transport to offer.
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+ #[cfg(target_os = "tvos")]
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+ Transport::Stdio { command, .. } => {
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+ bail!(
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+ "can't start {}: this platform can't run MCP servers as processes",
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+ command.display()
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+ );
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+ }
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Transport::Http {
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url,
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bearer,