Fix zsh completion panic

src/bin/cargo-flamegraph.rs

@@ -314,6 +314,7 @@ fn find_unique_target(kind: &[&str], pkg: Option<&str>) -> anyhow::Result<Binary
 
 fn main() -> anyhow::Result<()> {
     let Opts::Flamegraph(mut opt) = Opts::from_args();
+    opt.graph.check()?;
 
     let kind = if opt.bin.is_none()
         && opt.bench.is_none()

src/bin/flamegraph.rs

@@ -27,11 +27,10 @@ fn main() -> anyhow::Result<()> {
 
     if let Some(shell) = opt.completions {
         return match opt.trailing_arguments.is_empty() {
-            true => Ok(Opt::clap().gen_completions_to(
-                "flamegraph",
-                shell,
-                &mut std::io::stdout().lock(),
-            )),
+            true => {
+                Opt::clap().gen_completions_to("flamegraph", shell, &mut std::io::stdout().lock());
+                Ok(())
+            }
             false => {
                 return Err(anyhow!(
                     "command arguments cannot be used with --completions <completions>"
@@ -40,6 +39,8 @@ fn main() -> anyhow::Result<()> {
         };
     }
 
+    opt.graph.check()?;
+
     let workload = match (opt.pid, opt.trailing_arguments.is_empty()) {
         (Some(p), true) => Workload::Pid(p),
         (None, false) => Workload::Command(opt.trailing_arguments.clone()),

src/lib.rs

@@ -18,7 +18,7 @@ use inferno::collapse::dtrace::{Folder, Options as CollapseOptions};
 #[cfg(unix)]
 use signal_hook::consts::{SIGINT, SIGTERM};
 
-use anyhow::Context;
+use anyhow::{anyhow, Context};
 use inferno::{
     collapse::Collapse,
     flamegraph::color::Palette,
@@ -316,7 +316,7 @@ pub struct Options {
     frequency: Option<u32>,
 
     /// Custom command for invoking perf/dtrace
-    #[structopt(short = "c", long = "cmd", conflicts_with = "freq")]
+    #[structopt(short = "c", long = "cmd")]
     custom_cmd: Option<String>,
 
     #[structopt(flatten)]
@@ -327,18 +327,31 @@ pub struct Options {
     script_no_inline: bool,
 }
 
+impl Options {
+    pub fn check(&self) -> anyhow::Result<()> {
+        // Manually checking conflict because structopts `conflicts_with` leads
+        // to a panic in completion generation for zsh at the moment (see #158)
+        match self.frequency.is_some() && self.custom_cmd.is_some() {
+            true => Err(anyhow!(
+                "Cannot pass both a custom command and a frequency."
+            )),
+            false => Ok(()),
+        }
+    }
+}
+
 #[derive(Debug, structopt::StructOpt)]
 pub struct FlamegraphOptions {
     /// Colors are selected such that the color of a function does not change between runs
-    #[structopt(long = "deterministic", conflicts_with = "hash")]
+    #[structopt(long = "deterministic")]
     pub deterministic: bool,
 
     /// Plot the flame graph up-side-down
     #[structopt(short = "i", long = "inverted")]
     pub inverted: bool,
 
     /// Generate stack-reversed flame graph
-    #[structopt(long = "reverse", conflicts_with = "no-sort")]
+    #[structopt(long = "reverse")]
     pub reverse: bool,
 
     /// Set embedded notes in SVG