Error on changing dependencies

[fhars]

Describe the bug

Entangled errors out if an output file does no longer depend on one of its input files.

To Reproduce

Create two files that write to the same output file, then change the second on to write somewhere else:

mkdir test
cd test/
cat > input1.md <<'EOF'
``` {.c file=output1.c}
// hello from 1
```
EOF
cat > input2.md <<'EOF'
``` {.c file=output1.c}
// hello from 2
```
EOF
entangled tangle
# Fix the typo in input2.md
cat > input2.md <<'EOF'
``` {.c file=output2.c}
// hello from 2
```
EOF
entangled tangle

Output:

[09:18:06] INFO     Welcome to Entangled v2.4.2!
           INFO     create `output1.c`
[09:18:07] INFO     Welcome to Entangled v2.4.2!
           INFO     write `output1.c`
           INFO     create `output2.c`
           WARNING  `output1.c` newer than all of its sources: `input1.md`
           ERROR    conflicts found, breaking off (use `--force` to run anyway)

Expected behavior

entangled should detect that output1.c does no longer depend on input2.md but did before.

Additional comments

This may be related to #88 in that entangled seems to have problems handling structural changes to the dependency graph other that adding nodes and edges.

[jhidding]

Thanks for reporting this!
The problem is not so much the later chain of dependencies. Entangled detects that you're trying to update a target file from a single source file while the target file is more recent. The case could be that you have edited the target file and are overwriting those changes with the tangle. I'm trying to think if there's a way to make sure that we are allowed to overwrite the file, maybe through inspection of the filedb.