Make opts.maybe_sysroot non-optional

build_session_options always uses materialize_sysroot anyway.

src/librustdoc/config.rs

@@ -103,6 +103,8 @@ pub(crate) struct Options {
     /// compiling doctests from the crate.
     pub(crate) edition: Edition,
     /// The path to the sysroot. Used during the compilation process.
+    pub(crate) sysroot: PathBuf,
+    /// Has the same value as `sysroot` except is `None` when the user didn't pass `---sysroot`.
     pub(crate) maybe_sysroot: Option<PathBuf>,
     /// Lint information passed over the command-line.
     pub(crate) lint_opts: Vec<(String, Level)>,
@@ -202,6 +204,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             .field("unstable_options", &"...")
             .field("target", &self.target)
             .field("edition", &self.edition)
+            .field("sysroot", &self.sysroot)
             .field("maybe_sysroot", &self.maybe_sysroot)
             .field("lint_opts", &self.lint_opts)
             .field("describe_lints", &self.describe_lints)
@@ -834,6 +837,7 @@ fn println_condition(condition: Condition) {
             unstable_opts_strs,
             target,
             edition,
+            sysroot,
             maybe_sysroot,
             lint_opts,
             describe_lints,

src/librustdoc/core.rs

@@ -210,7 +210,7 @@ pub(crate) fn create_config(
         unstable_opts,
         target,
         edition,
-        maybe_sysroot,
+        sysroot,
         lint_opts,
         describe_lints,
         lint_cap,
@@ -253,7 +253,7 @@ pub(crate) fn create_config(
     let test = scrape_examples_options.map(|opts| opts.scrape_tests).unwrap_or(false);
     // plays with error output here!
     let sessopts = config::Options {
-        maybe_sysroot,
+        sysroot,
         search_paths: libs,
         crate_types,
         lint_opts,

src/librustdoc/doctest.rs

@@ -158,7 +158,7 @@ pub(crate) fn run(dcx: DiagCtxtHandle<'_>, input: Input, options: RustdocOptions
         if options.proc_macro_crate { vec![CrateType::ProcMacro] } else { vec![CrateType::Rlib] };
 
     let sessopts = config::Options {
-        maybe_sysroot: options.maybe_sysroot.clone(),
+        sysroot: options.sysroot.clone(),
         search_paths: options.libs.clone(),
         crate_types,
         lint_opts,