Improve dependency management

[peppergrayxyz]

Description

Currently, gcc, git and ~/.chossenim/current are needed to use nim:

• nimble requires git nimble#1319
• Unable to change choosenim directory #24281
• choosenim breaks nim when used with custom paths choosenim#61
• C compiler is hardcoded choosenim#62

It should just work with CC provided

Nim Version

• choosenim v0.8.10
• Nim 2.2.0

Current Output

$ CC=zig choosenim --choosenimDir:$nimpath/my-choosenim --nimbleDir:$nimpath/my-nimbledir stable
     Error: No C compiler found. Nim compiler requires a C compiler.
        ... Install gcc using your favourite package manager.
$ export PATH=$nimpath/my-nimbledir/bin:$PATH
$ CC=zig nimble rel
       Tip: 1 messages have been suppressed, use --verbose to show them.
tools.nim(52)            doCmdEx

    Error:  'git' not in PATH.

Expected Output

$ choosenim --choosenimDir:$nimpath/my-choosenim --nimbleDir:$nimpath/my-nimbledir stable
$ export PATH=$nimpath/my-nimbledir/bin:$PATH
$ nimble rel
    Success

Known Workarounds

# config
cc=zig
nim_path="/home/user/dev/choosenim"
choosenim_path="my-choosenim"
nimble_path="my-nimble"
release="0.8.4"

### get & unpack
mkdir -p "$nim_path"
pushd "$nim_path"
wget -O "choosenim" https://github.com/nim-lang/choosenim/releases/download/v${release}/choosenim-${release}_linux_amd64
chmod +x "choosenim"

### install

# nim-lang#62 - gcc is hard coded
nim_patch_path="`pwd`"
printf "#\!/bin/sh\n\$CC\n" > "$nim_patch_path/gcc"
chmod +x "$nim_patch_path/gcc"

# run choosenim with custom paths
PATH="$nim_patch_path:$PATH" CC="$cc" ./choosenim --choosenimDir:"$choosenim_path" --nimbleDir:"$nimble_path" --firstInstall stable

# nim-lang#1319 - setup fake git
nimble_git="$nimble_path/bin/git"
printf "#\!/bin/sh\nif command -v /usr/bin/git 2>&1 >/dev/null; then /usr/bin/git "\$@"; else exit 0; fi\n" > "$nimble_git"
chmod +x "$nimble_git"

# choosenim#61
mkdir -p ".choosenim"
ln -s "../$choosenim_path/current" ".choosenim/current"

popd

### run

# setup env
export PATH="$nim_path/$nimble_path/bin:$PATH"

# run nimble (with fake home dir Nim#24281)
HOME=$nim_path nimble rel

Additional Information

No response

[Araq]

Plenty of people, myself included use Nim without any choosenim. You can even use Nim without Nimble. The C compiler is hardcoded because we expoit its individual non-standard features and Zig is just a clang as far as Nim is concerned, easily configurable.