how to cascade feature in workspace

Question

My rust project is constructed from a workspace with many (50+) sub-crates in the workspace.

I want to cascade a feature flag (sharing the same name) through all the dependency tree (all the sub-crates which are depending on each other).

example

# I have many shared crates. some sub-crates depend on other subcrates 

package/Cargo.toml

[dependencies]
shared_package1 = {path = "../shared_package1"} 
shared_package2 = {path = "../shared_package2"}
shared_package3 = {path = "../shared_package3"}
...
shared_package100 = {path = "../shared_package100"}

[features]
shared_feature = []

shared_package2/Cargo.toml
[dependencies]
shared_package3 = {path = "../shared_package3"}
...
shared_package100 = {path = "../shared_package100"}

[features]
shared_feature = []

....
....
shared_package100/Cargo.toml
[dependencies]
[features]
shared_feature = []

now that I've added shared_feature I resort to manually adding the feature configuration to my 100 crates and dependencies (need to figure out which feature flags need to be modified) and this is error prone (I'm tripping myself up writing the question :) ).

package/Cargo.toml

[features]
# turn on shared_feature flag for all the dependencies now and cascade it down
shared_feature = ["shared_package1/shared_feature", "shared_package2/shared_feature", .... "shared_package100/shared_feature"]


shared_package1/Cargo.toml
...
[features]
# turn it on....
shared_feature = ["shared_package2/shared_feature", "shared_package3/shared_feature", .... "shared_package100/shared_feature"]

# doing this for all the tree
...
...
shared_package99/Cargo.toml
...
[features]
shared_feature = [....]

I've tried to grep through Cargo.toml files but seems very cumbersome.

Edit:

This toy script helps to locate the feature flags

# make sure you have these installed
# https://crates.io/crates/cargo-get
# cargo install cargo-get
# cargo install feature

declare -A cache
# feature name you are searching for
feature=$1
echo "Cargo.toml files with $feature feature flags"

for toml in $(find . -name Cargo.toml)
do
  crate=$(cargo get -n --root $toml 2>/dev/null)
  if [ -z "$crate" ]
  then
    continue
  fi
  hasfeatue=$(cargo feature $crate 2>/dev/null | grep $feature)
  if [ -z "$hasfeatue" ]
  then
    cache[$crate]=0
    continue
  fi
  cache[$crate]=1
  echo $toml $crate
  echo $hasfeatue
  for sub in $(cargo tree -p $crate --depth 1 --prefix=none  | cut -d' ' -f1)
  do
    if [ $sub = $crate ]
    then
      continue
    fi
    if [ ! -z ${cache[$sub]} ]
    then
        if [ ${cache[$sub]} -eq 1 ]
        then
          echo "\tsub: ${sub}"
        fi
        continue
    fi
    res=$(cargo feature $sub 2>/dev/null | grep $feature 2>/dev/null)
    if [ -z "$res" ]
    then
      cache[$sub]=0
      continue
    fi
    cache[$sub]=1
    echo "\tsub: ${sub}"
  done
done