yarn/pyenv/rvm/etc - check for presence before doing anything

bashrc.d/nvm.bash

@@ -1,3 +1,6 @@
+if [ -d "$HOME/.nvm" ] ; then
   export NVM_DIR="$HOME/.nvm"
   [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
   [ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion
+fi
+

bashrc.d/pyenv.bash

@@ -1,5 +1,5 @@
+if [ -d "$HOME/.pyenv" ] ; then
   export PYENV_ROOT="$HOME/.pyenv"
-if [ -d "$PYENV_ROOT" ] ; then
   command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"
   eval "$(pyenv init -)"
 fi

bashrc.d/rvm.bash

@@ -1,2 +1,4 @@
 # Add RVM to PATH for scripting. Make sure this is the last PATH variable change.
+if [ -d "$HOME/.rvm/bin" ] ; then
   addpath "$HOME/.rvm/bin"
+fi

bashrc.d/yarn.bash

@@ -1,2 +1,4 @@
+if [ "$HOME/.yarn/bin" ] ; then
   addpath "$HOME/.yarn/bin"
   addpath "$HOME/.config/yarn/global/node_modules/.bin"
+fi