alexander@alexander-pc:~/code/test/debugger/minidbg$ git submodule init
Submodule 'ext/libelfin' (https://github.com/aclements/libelfin.git) registered for path 'ext/libelfin'
Submodule 'ext/linenoise' (https://github.com/antirez/linenoise.git) registered for path 'ext/linenoise'
alexander@alexander-pc:~/code/test/debugger/minidbg$ git submodule update
Cloning into 'ext/libelfin'...
remote: Counting objects: 818, done.
remote: Total 818 (delta 0), reused 0 (delta 0), pack-reused 818
Receiving objects: 100% (818/818), 190.57 KiB | 235.00 KiB/s, done.
Resolving deltas: 100% (487/487), done.
Checking connectivity... done.
fatal: reference is not a tree: cc25b47c11f6798f79f09ec2345b18d663f9d548
Cloning into 'ext/linenoise'...
remote: Counting objects: 396, done.
remote: Compressing objects: 100% (3/3), done.
remote: Total 396 (delta 0), reused 1 (delta 0), pack-reused 393
Receiving objects: 100% (396/396), 165.21 KiB | 248.00 KiB/s, done.
Resolving deltas: 100% (225/225), done.
Checking connectivity... done.
Submodule path 'ext/linenoise': checked out 'c894b9e59f02203dbe4e2be657572cf88c4230c3'
Unable to checkout 'cc25b47c11f6798f79f09ec2345b18d663f9d548' in submodule path 'ext/libelfin'
I was able to fix it by changing the submodule url to your fork.
alexander@alexander-pc:~/code/test/debugger/minidbg$ git diff
diff --git a/.gitmodules b/.gitmodules
index 13aada1..4017271 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,6 +1,6 @@
[submodule "ext/libelfin"]
path = ext/libelfin
- url = https://github.com/aclements/libelfin.git
+ url = https://github.com/TartanLlama/libelfin.git
[submodule "ext/linenoise"]
path = ext/linenoise
url = https://github.com/antirez/linenoise.git