RbConfig::MAKEFILE_CONFIG['MAKEDIRS'] set incorrectly on Debian 10 aarch64

[ramereth]

Version:

omnibus-toolchain 2.0.2

Component           Installed Version   Version GUID                                                              Overridden From   
------------------------------------------------------------------------------------------------------------------------------------
bash                5.0                 sha256:b4a80f2ac66170b2913efbfb9f2594f1f76c7b1afd11f799e22035d63077fb4d   
bundler             2.0.2               
bzip2               1.0.8               sha256:ab5a03176ee106d3f0fa90e381da478ddae405918153cca248e682cd0c4a2269   
cacerts             2019-10-16          sha256:5cd8052fcf548ba7e08899d8458a32942bf70450c9af67a0850b4c711804a2e4   
config_guess        master              git:84f04b02a7e2fc8eaa9d52deee5f6d57b06fe447                              
curl                7.68.0              sha256:1dd7604e418b0b9a9077f62f763f6684c1b092a7bc17e3f354b8ad5c964d7358   
expat               2.1.0               md5:dd7dab7a5fea97d2a6a43f511449b7cd                                      
git                 2.26.2              sha256:e1c17777528f55696815ef33587b1d20f5eec246669f3b839d15dbfffad9c121   
gtar                1.32                sha256:b59549594d91d84ee00c99cf2541a3330fed3a42c440503326dab767f2fbb96c   1.30              
helper-gems         2.0.2               
helper-sh           2.0.2               
libarchive          3.4.2               sha256:b60d58d12632ecf1e8fad7316dc82c6b9738a35625746b47ecdcaf4aed176176   
libedit             20120601-3.0        md5:e50f6a7afb4de00c81650f7b1a0f5aea                                      
libffi              3.2.1               md5:83b89587607e3eb65c70d361f13bab43                                      
libiconv            1.15                sha256:ccf536620a45458d26ba83887a983b96827001e92a13847b45e4925cc8913178   
liblzma             5.2.4               sha256:b512f3b726d3b37b6dc4c8570e137b9311e7552e8ccbab4d39d47ce5f4177145   
libtool             2.4.6               md5:addf44b646ddb4e3919805aa88fa7c5e                                      
libxml2             2.9.10              sha256:aafee193ffb8fe0c82d4afef6ef91972cbaf5feea100edc2f262750611b4be1f   
libxslt             1.1.34              sha256:98b1bd46d6792925ad2dfe9a87452ea2adebf69dcb9919ffd55bf926a7f93f7f   
libyaml             0.1.7               sha256:8088e457264a98ba451a90b8661fcb4f9d6f478f7265d48322a196cec2480729   
make                4.2.1               sha256:e40b8f018c1da64edd1cc9a6fce5fa63b2e707e404e20cad91fbae337c98a5b7   
makedepend          1.0.5               md5:efb2d7c7e22840947863efaedc175747                                      
ncurses             5.9                 md5:8cb9c412e5f2d96bc6f459aa8c6282a1                                      
nokogiri            2.0.2               
omnibus-toolchain   1.0.0               
openssl             1.0.2u              sha256:ecd0c6ffb493dd06707d38b14bb4d8c2288bb7033735606569d8f90f89669d16   
patch               2.7.6               sha256:8cf86e00ad3aaa6d26aca30640e86b0e3e1f395ed99f189b06d4c9f74bc58a4e   
pcre                8.38                md5:8a353fe1450216b6655dfcf3561716d9                                      
pkg-config-lite     0.28-1              md5:61f05feb6bab0a6bbfab4b6e3b2f44b6                                      
preparation         1.0.0               
ruby                2.6.5               sha256:66976b716ecc1fd34f9b7c3c2b07bbd37631815377a2e3e85a5b194cfdcbed7d   2.6.6             
rubygems            2.0.2               
util-macros         1.18.0              md5:fd0ba21b3179703c071bbb4c3e5fb0f4                                      
xproto              7.0.25              md5:a47db46cb117805bd6947aa5928a7436                                      
zlib                1.2.11              sha256:c3e5e9fdd5004dcb542feda5ee4f0ff0744628baf8ed2dd5d66f8ca1197cb1a1   

Environment:

Debian 10 aarch64

Scenario:

Trying to build Chef on Debian 10 aarch64 but fails to install the ffi gem with the following error:

make: /usr/bin/mkdir: Command not found

On a Debian 10 aarch64 system, mkdir resides in /bin/mkdir NOT /usr/bin/mkdir. It appears that Ruby was built with this set:

/opt/omnibus-toolchain/embedded/bin/irb 
irb(main):001:0> RbConfig::MAKEFILE_CONFIG['MAKEDIRS']
=> "/usr/bin/mkdir -p"

If I make a symlink to that location the installation continues.

Steps to Reproduce:

1. Install omnibus-toolchain 2.0.2 on Debian 10 aarch64
2. git clone https://github.com/chef/chef
3. /opt/omnibus-toolchain/bin/load-omnibus-toolchain
4. cd chef/omnibus
5. bundle install --without development
6. bundle exec omnibus build chef

Expected Result:

[What are you expecting to happen as the consequence of above reproduction steps?]

Actual Result:

[What actually happens after the reproduction steps?]

[ramereth]

FWIW this is still happening.