As explained here: https://docs.conda.io/projects/conda-build/en/latest/resources/compiler-tools.html

1) All of the executables in a compiler package are "prefixed." Instead of gcc, the executable name of the compiler you use will be something like x86_64-conda_cos6-linux-gnu-gcc

2) Many build tools such as make and CMake search by default for a compiler named simply gcc, so we set environment variables to point these tools to the correct compiler.

So if you run:

conda create -n cc_env gcc_linux-64
conda activate cc_env
ls $CONDA_PREFIX/bin

You will see a bunch of compiler tools with the prefixed name:

c89                                    x86_64-conda_cos6-linux-gnu-ct-ng.config  x86_64-conda_cos6-linux-gnu-gcov-dump  x86_64-conda_cos6-linux-gnu-objdump
c99                                    x86_64-conda_cos6-linux-gnu-dwp           x86_64-conda_cos6-linux-gnu-gcov-tool  x86_64-conda_cos6-linux-gnu-ranlib
x86_64-conda_cos6-linux-gnu-addr2line  x86_64-conda_cos6-linux-gnu-elfedit       x86_64-conda_cos6-linux-gnu-gprof      x86_64-conda_cos6-linux-gnu-readelf
x86_64-conda_cos6-linux-gnu-ar         x86_64-conda_cos6-linux-gnu-gcc           x86_64-conda_cos6-linux-gnu-ld         x86_64-conda_cos6-linux-gnu-size
x86_64-conda_cos6-linux-gnu-as         x86_64-conda_cos6-linux-gnu-gcc-ar        x86_64-conda_cos6-linux-gnu-ld.bfd     x86_64-conda_cos6-linux-gnu-strings
x86_64-conda_cos6-linux-gnu-cc         x86_64-conda_cos6-linux-gnu-gcc-nm        x86_64-conda_cos6-linux-gnu-ld.gold    x86_64-conda_cos6-linux-gnu-strip
x86_64-conda_cos6-linux-gnu-c++filt    x86_64-conda_cos6-linux-gnu-gcc-ranlib    x86_64-conda_cos6-linux-gnu-nm
x86_64-conda_cos6-linux-gnu-cpp        x86_64-conda_cos6-linux-gnu-gcov          x86_64-conda_cos6-linux-gnu-objcopy

This is ok because environment variables like CC and CPP are pointing to the compiler to use, and commands like make know to use these variable:

$ echo $CC
/home/builder/anaconda3/envs/cc_env/bin/x86_64-conda_cos6-linux-gnu-cc
$ echo $CPP
/home/builder/anaconda3/envs/cc_env/bin/x86_64-conda_cos6-linux-gnu-cpp

For more info on what environment variables make is aware of see: https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html

I got gcc v7, using miniconda v4.7.12:

conda install -c anaconda gcc_linux-64

More details here: https://www.anaconda.com/utilizing-the-new-compilers-in-anaconda-distribution-5/

https://anaconda.org/anaconda/gcc_linux-64/files

$ x86_64-conda_cos6-linux-gnu-gcc --version
x86_64-conda_cos6-linux-gnu-gcc (crosstool-NG 1.23.0.449-a04d0) 7.3.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

I'm not sure how exactly the packages relate, but I needed to install the gcc package to resolve some sort of load error. Given that gcc didn't produce any results, I ran a quick

Copy$ conda search gcc

Which yielded, among other things, gcc_linux-64. After

Copy$ conda install gcc_linux-64

My issue went away, despite the fact that which gcc still pointed to the system install 🤷‍♂️

Just to share, not sure it will help you. However it shows that in standard conditions it is possible to use the conda gcc as described in the documentation instead of the system gcc.

# system gcc
which gcc && gcc --version
# /usr/bin/gcc
# gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0

# creating a conda env with gcc
conda create -n gcc gcc
# activate the environment
conda activating gcc
which gcc && gcc --version
# /opt/conda/envs/gcc/bin/gcc
# gcc (GCC) 11.2.0

Here is the list of packages installed on a fresh environment created with only gcc.

# packages in environment at /opt/conda/envs/gcc:
#
# Name                    Version                   Build  Channel
_libgcc_mutex             0.1                 conda_forge    conda-forge
_openmp_mutex             4.5                       1_gnu    conda-forge
binutils_impl_linux-64    2.36.1               h193b22a_2    conda-forge
gcc                       11.2.0               h702ea55_2    conda-forge
gcc_impl_linux-64         11.2.0              h82a94d6_11    conda-forge
kernel-headers_linux-64   2.6.32              he073ed8_15    conda-forge
ld_impl_linux-64          2.36.1               hea4e1c9_2    conda-forge
libgcc-devel_linux-64     11.2.0              h0952999_11    conda-forge
libgcc-ng                 11.2.0              h1d223b6_11    conda-forge
libgomp                   11.2.0              h1d223b6_11    conda-forge
libsanitizer              11.2.0              he4da1e4_11    conda-forge
libstdcxx-ng              11.2.0              he4da1e4_11    conda-forge
sysroot_linux-64          2.12                he073ed8_15    conda-forge