1. Clone Git Prompt support https://github.com/jimeh/git-aware-prompt to ~/.bash/ (~/.bash/git-aware-prompt/)
2. Add enclosed Mercurial Prompt support to ~/.bash/ (~/.bash/hg_prompt.sh)
3. Integrate both into your ~/.bash_profile with:

# git prompt

export GITAWAREPROMPT=~/.bash/git-aware-prompt
source "${GITAWAREPROMPT}/main.sh"

# mercurial prompt

source ~/.bash/hg_prompt.sh

# combined prompt

scm_branch() {
    if [ -z "$git_branch" ]
    then
        local _hg_branch=$(hg_branch)
        if [ -z "$_hg_branch" ]
        then
            return
        else
            echo -n "("$_hg_branch")"
        fi
    else
        echo -n $git_branch
    fi
}

scm_dirty() {
    if [ -z "$git_dirty" ]
    then
        local _hg_dirty=$(hg_dirty)
        if [ -z "$_hg_dirty" ]
        then
            return
        else
            echo -n "$_hg_dirty"
        fi
    else
        echo -n "$git_dirty"
    fi
}

# install prompt

export PS1="\u@\h \w \[$txtcyn\]\$(scm_branch)\[$txtred\]\$(scm_dirty)\[$txtrst\]\$ "

Then enjoy seeing directory sensitive prompts when CD'ing into git and hg repos such as: nr@Computer ~/proj/slash (features/main)*$ and nr@Computer ~/proj/editor (cloud/time)!$. Note the hg support currently feels 'slow'.