Adding a timout command when running the executable file could cause wrong coverage result

[cicilzx]

I'm not sure it is a bug or my incorrect behaviour. Here is what I did:

1. A simple Rust code:

   fn main() {}

2. Build, run, and get coverage information:

   rustc -C instrument-coverage file.rs
   ./file
   grcov . --binary-path ./file -s ./file.rs -t lcov --branch --ignore-not-existing --ignore '../*' --ignore "/*" -o ./lcov1.info

   The rusult goes well, like this:

   TN:
   SF:
   FN:1,file10::main
   FNDA:1,file10::main
   FNF:1
   FNH:1
   BRF:0
   BRH:0
   DA:1,1
   DA:2,1
   DA:3,1
   LF:3
   LH:3
   end_of_record

3. But if I add a timeout command like this:

   rustc -C instrument-coverage file.rs
   timeout 30m ./file
   grcov . --binary-path ./file -s ./file.rs -t lcov --branch --ignore-not-existing --ignore '../*' --ignore "/*" -o ./lcov2.info

   The coverage result is output like this:

   TN:
   SF:
   FN:1,file10::main
   FNDA:1,file10::main
   FNF:1
   FNH:1
   BRF:0
   BRH:0
   DA:1,1
   DA:2,1
   DA:3,1
   LF:3
   LH:3
   end_of_record
   SF:
   FN:1,file10::main
   FNDA:1,file10::main
   FNF:1
   FNH:1
   BRF:0
   BRH:0
   DA:1,1
   DA:2,1
   DA:3,1
   LF:3
   LH:3
   end_of_record

   I don't understand why there are two end_of_record, and the second group of coverage infomation seems to be odd. Is this a bug of rustc or grcov? Or is there something wrong with the way I'm doing it that causes the results to be incorrect?