feat: add option to not require a t_aux file to be present

The `FFI_USE_FIXED_ROWS_TO_DISCARD` variable will make the proofs
ignore the `FIL_PROOFS_ROWS_TO_DISCARD` setting, hence not relying
on a `t_aux` file to be present. If enabled, then no `t_aux` file
will be written by the proofs and a hard-coded value for
`FIL_PROOFS_ROWS_TO_DISCARD` will be used.

install-filcrypto

@@ -208,11 +208,19 @@ build_from_source() {
         use_multicore_sdr=""
     fi
 
+    # By default the number or rows to discard of the TreeRLast can be set via
+    # `FIL_PROOFS_ROWS_TO_DISCARD`. When SupraSeal PC2 is used, then this
+    # number is fixed.
+    use_fixed_rows_to_discard=""
+    if [ "${FFI_USE_FIXED_ROWS_TO_DISCARD}" == "1" ]; then
+        use_fixed_rows_to_discard=",fixed-rows-to-discard"
+    fi
+
     # Add feature specific rust flags as needed here.
     if [ "${FFI_USE_BLST_PORTABLE}" == "1" ]; then
-        additional_flags="${additional_flags} --no-default-features --features ${use_multicore_sdr},blst-portable${gpu_flags}"
+        additional_flags="${additional_flags} --no-default-features --features ${use_multicore_sdr},blst-portable${gpu_flags}${use_fixed_rows_to_discard}"
     else
-        additional_flags="${additional_flags} --no-default-features --features ${use_multicore_sdr}${gpu_flags}"
+        additional_flags="${additional_flags} --no-default-features --features ${use_multicore_sdr}${gpu_flags}${use_fixed_rows_to_discard}"
     fi
 
     echo "Using additional build flags: ${additional_flags}"

rust/Cargo.toml

@@ -61,3 +61,12 @@ cuda-supraseal = ["filecoin-proofs-api/cuda-supraseal", "rust-gpu-tools/cuda", "
 opencl = ["filecoin-proofs-api/opencl", "rust-gpu-tools/opencl", "fvm2/opencl", "fvm3/opencl", "fvm4/opencl"]
 multicore-sdr = ["filecoin-proofs-api/multicore-sdr"]
 c-headers = ["safer-ffi/headers"]
+# This feature enables a fixed number of discarded rows for TreeR. The `FIL_PROOFS_ROWS_TO_DISCARD`
+# setting is ignored, no `TemporaryAux` file will be written.
+fixed-rows-to-discard = ["filecoin-proofs-api/fixed-rows-to-discard"]
+
+[patch.crates-io]
+filecoin-hashers = { git = "https://github.com/filecoin-project/rust-fil-proofs", branch = "master" }
+filecoin-proofs = { git = "https://github.com/filecoin-project/rust-fil-proofs", branch = "master" }
+filecoin-proofs-api = { git = "https://github.com/filecoin-project/rust-filecoin-proofs-api", branch = "fixed-rows-to-discard" }
+storage-proofs-core = { git = "https://github.com/filecoin-project/rust-fil-proofs", branch = "master" }