./install.py --rust-completer => error[E0423]: expected function, tuple struct or tuple variant, found struct ast::Name

[yanqd0]

Issue Prelude

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  Frequently Asked Questions section.
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  search.)
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  version) I am using.
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  my issue, including what I expected to happen and what actually happened.
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  of install.py (or cmake/make/ninja) including its invocation
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  that any help I receive is a selfless, heartfelt gift of their free time. I
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Thank you for adhering to this process! It ensures your issue is resolved
quickly and that neither your nor our time is needlessly wasted.

Issue Details

When installing YCM with Rust support, I meet a compile error with rustc 1.41.0 version.

$ ./install.py --rust-completer
...
[100%] Linking C shared library /home/y00445480/.vim/vim-plug/YouCompleteMe/third_party/ycmd/third_party/cregex/regex_3/_regex.so
[100%] Built target _regex
   Compiling url v1.5.1
   Compiling syntex_syntax v0.54.0
   Compiling syntex_syntax v0.52.0
error[E0713]: borrow may still be in use when destructor runs
   --> /home/y00445480/.cargo/registry/src/github.com-1ecc6299db9ec823/url-1.5.1/src/form_urlencoded.rs:251:40
    |
249 | impl<'a> Target for ::UrlQuery<'a> {
    |      -- lifetime `'a` defined here
250 |     fn as_mut_string(&mut self) -> &mut String { &mut self.url.serialization }
251 |     fn finish(self) -> &'a mut ::Url { self.url }
    |                                        ^^^^^^^^ - here, drop of `self` needs exclusive access to `*self.url`, because the type `UrlQuery<'_>` implements the `Drop` trait
    |                                        |
    |                                        returning this value requires that `*self.url` is borrowed for `'a`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0713`.
error: could not compile `url`.
warning: build failed, waiting for other jobs to finish...
error[E0423]: expected function, tuple struct or tuple variant, found struct `ast::Name`
   --> /home/y00445480/.cargo/registry/src/github.com-1ecc6299db9ec823/syntex_syntax-0.54.0/src/symbol.rs:146:27
    |
146 |                       name: ast::Name($index),
    |                             ^^^^^^^^^
...
165 | / declare_keywords! {
166 | |     // Invalid identifier
167 | |     (0,  Invalid,        "")
168 | |
...   |
231 | |     (56, CrateRoot, "{{root}}")
232 | | }
    | |_- in this macro invocation

error[E0423]: expected function, tuple struct or tuple variant, found struct `ast::Name`
   --> /home/y00445480/.cargo/registry/src/github.com-1ecc6299db9ec823/syntex_syntax-0.52.0/src/symbol.rs:146:27
    |
146 |                       name: ast::Name($index),
    |                             ^^^^^^^^^
...
165 | / declare_keywords! {
166 | |     // Invalid identifier
167 | |     (0,  Invalid,        "")
168 | |
...   |
228 | |     (55, Union,          "union")
229 | | }
    | |_- in this macro invocation

error: aborting due to previous error

For more information about this error, try `rustc --explain E0423`.
error: could not compile `syntex_syntax`.
warning: build failed, waiting for other jobs to finish...
error: aborting due to previous error

For more information about this error, try `rustc --explain E0423`.
error: could not compile `syntex_syntax`.

To learn more, run the command again with --verbose.

More information about E0423:

$ rustc --explain E0423
An identifier was used like a function name or a value was expected and the
identifier exists but it belongs to a different namespace.

For (an erroneous) example, here a `struct` variant name were used as a
function:

```
struct Foo { a: bool };

let f = Foo();
// error: expected function, tuple struct or tuple variant, found `Foo`
// `Foo` is a struct name, but this expression uses it like a function name
```

Please verify you didn't misspell the name of what you actually wanted to use
here. Example:

```
fn Foo() -> u32 { 0 }

let f = Foo(); // ok!
```

It is common to forget the trailing `!` on macro invocations, which would also
yield this error:

```
println("");
// error: expected function, tuple struct or tuple variant,
// found macro `println`
// did you mean `println!(...)`? (notice the trailing `!`)
```

Another case where this error is emitted is when a value is expected, but
something else is found:

```
pub mod a {
    pub const I: i32 = 1;
}

fn h1() -> i32 {
    a.I
    //~^ ERROR expected value, found module `a`
    // did you mean `a::I`?
}
```

Environments

$ lsb_release -a
LSB Version:    core-9.20170808ubuntu1-noarch:printing-9.20170808ubuntu1-noarch:security-9.20170808ubuntu1-noarch
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.3 LTS
Release:        18.04
Codename:       bionic
$ rustc --version -v
rustc 1.41.0 (5e1a79984 2020-01-27)
binary: rustc
commit-hash: 5e1a799842ba6ed4a57e91f7ab9435947482f7d8
commit-date: 2020-01-27
host: x86_64-unknown-linux-gnu
release: 1.41.0
LLVM version: 9.0

[bstaletic]

   Compiling url v1.5.1
   Compiling syntex_syntax v0.54.0
   Compiling syntex_syntax v0.52.0

This implies you're on an ancient YCM. Please update YCM and the submodules and rerun the script.

[yanqd0]

There is another similar issue: rust/lang#68729.

[yanqd0]

   Compiling url v1.5.1
   Compiling syntex_syntax v0.54.0
   Compiling syntex_syntax v0.52.0

This implies you're on an ancient YCM. Please update YCM and the submodules and rerun the script.

Thanks!

I tried git pull before creating this issue, but not working. git submodule update --init works.

[bstaletic]

Great. We can close this now.