How should I fix the configure.yaml file?

I am trying to install hpctoolkit using spack. In order to do that, I executed :

git clone https://github.com/spack/spack.git
cd spack/share/spack
source setup-env.sh 
spack fetch -D hpctoolkit
spack install hpctoolkit 

In order to see the available compilers, I need to look at the content of compilers.yaml. Here is its content:

lcompilers:
- compiler:
    spec: clang@10.0.0
    paths:
      cc: /usr/bin/clang
      cxx: /usr/bin/clang++
      f77: null
      fc: null
    flags: {}
    operating_system: ubuntu20.04
    target: x86_64
    modules: []
    environment: {}
    extra_rpaths: []
- compiler:
    spec: clang@7.0.1
    paths:
      cc: null
      cxx: null
      f77: /usr/bin/flang
      fc: /usr/bin/flang
    flags: {}
    operating_system: ubuntu20.04
    target: x86_64
    modules: []
    environment: {}
    extra_rpaths: []
    
- compiler:
    spec: gcc@10.2.0
    paths:
      cc: /usr/bin/gcc-10
      cxx: null
      f77: /usr/bin/gfortran-10
      fc: /usr/bin/gfortran-10
    flags: {}
    operating_system: ubuntu20.04
    target: x86_64
    modules: []
    environment: {}
    extra_rpaths: []

As you can see here I have 2 compilers which are clang (2 instances) and gcc. I thought the file is properly written until I executed this command:

spack compiler list  

which gave me the following error:

==> Available compilers
==> Error: /home/hakim/.spack/linux/compilers.yaml:1: Additional properties are not allowed ('lcompilers' was unexpected)

The file worked perfectly before I modified it. I deleted a part which represents an other version of gcc which is gcc@9.3.0 (Spack notation).

The error mentions that 'lcompilers' was unexpected but I'm quite sure it was there before I modify the file. All I did was deleting the old version of gcc.