The General FAQ has been reorganized and relocated to https://z.cash/support/faq.html. Please check there for the latest updates to our frequently asked questions. The following is a list of questions for Troubleshooting zcashd, the core Zcash client software.
64-bit Linux (easiest with a Debian-based distribution)A compiler for C++11 if building from source. Gcc 6.x and above has full C++11 support, and gcc 4.8 and above supports some but not all features. Zcash will not compile with versions of gcc lower than 4.8.At least 4GB of RAM to generate shielded transactions.At least 8GB of RAM to successfully run all of the tests.
Zcash runs on port numbers that are 100 less than the corresponding Bitcoin port number. They are:
8232for mainnet RPC
8233for mainnet peer-to-peer network
18232for testnet RPC
18233for testnet peer-to-peer network
Building from source¶
If you did not build by running build.sh, you will encounter errors. Be sure to build with:
$ ./zcutil/build.sh -j$(nproc)
If you don’t have nproc, then substitute the number of your processors.
Error message: g++: internal compiler error: Killed (program cc1plus)
This means your system does not have enough memory for the building process and has failed. Please allocate at least 4GB of computer memory for this process and try again.
Error message: 'runtime_error' (or other variable) is not a member of 'std'. compilation terminated due to -Wfatal-errors. ``
Check your compiler version and ensure that it support C++11. If you’re using a version of gcc below 4.8.x, you will need to upgrade.
Error message: gtest failing with undefined reference ``
If you are developing on different branches of Zcash, there may be an issue with different versions of linked libraries. Try
make clean and build again.
could not load param file at /home/rebroad/.zcash-params/sprout-verifying.key
You didn’t fetch the parameters necessary for zk-SNARK proofs. If you installed the Debian package, run zcash-fetch-params. If you built from source, run ./zcutil/fetch-params.sh.
zcashd crashes with the message:
``std::bad_alloc`` or ``St13runtime_exception``
These messages indicate that your computer has run out of memory for running zcashd. This will most likely happen with mining nodes which require more resources than a full node without running a miner. This can also happen while creating a transaction involving a z-address. You’ll need to allocate at least 4GB memory for these transactions.
To get help with the RPC interface from the command line, use zcash-cli help to list all commands.
To get help with a particular command, use
zcash-cli help $COMMAND.
There is also additional documentation under Zcash Payment API .
zcash-cli` stops responding after I use the command `z_importkey
The command has added the key, but your node is currently scanning the blockchain for any transactions related to that key, causing there to be a delay before it returns. This immediate rescan is the default setting for z_importkey, which you can override by adding false to the command if you simply want to import the key, i.e. zcash-cli z_importkey $KEY false
If, when attempting to execute the
sendrawtransaction RPC method, you receive the error:
AcceptToMemoryPool: absurdly high fees
This is most likely caused by not specifying an output address to receive the change when creating the transaction (
createrawtransaction). This RPC call, unlike
z_sendmany, does not do this automatically.
createrawtransaction, the fee is simply the sum of the inputs minus the sum of the outputs. If this difference is larger than 0.0021 ZEC (210000 zatoshis), the assumption is that this is unintentional, and the transaction is not sent. If you really do wish to send a transaction with a large fee, add
true to the end of the
sendrawtransaction command line. This will allow an arbitrarily high fee.
What if my question isn’t answered here?
First search the issues section (https://github.com/zcash/zcash/issues) to see if someone else has posted a similar issue and if not, feel free to report your problem there. Please provide as much information about what you’ve tried and what failed so others can properly assess your situation to help.
If you have ran into any issues upgrading to Overwinter, please see the Network Upgrade Developer Guide