Instead of maintaining not-easily-tested instructions for building BerkeleyDB
in doc/build-unix.md, package the installation as a script in contrib/. This
allows shared usage from a number of contexts, e.g. Docker.
Thanks to @jonasschnelli, @laanwj for feedback.
89f0312 Remove redundant pwallet nullptr check (Matt Corallo)
c4784b5 Add a dev notes document describing the new wallet RPC blocking (Matt Corallo)
3ea8b75 Give ZMQ consistent order with UpdatedBlockTip on scheduler thread (Matt Corallo)
cb06edf Fix wallet RPC race by waiting for callbacks in sendrawtransaction (Matt Corallo)
e545ded Also call other wallet notify callbacks in scheduler thread (Matt Corallo)
17220d6 Use callbacks to cache whether wallet transactions are in mempool (Matt Corallo)
5d67a78 Add calls to CWallet::BlockUntilSyncedToCurrentChain() in RPCs (Matt Corallo)
5ee3172 Add CWallet::BlockUntilSyncedToCurrentChain() (Matt Corallo)
0b2f42d Add CallFunctionInQueue to wait on validation interface queue drain (Matt Corallo)
2b4b345 Add ability to assert a lock is not held in DEBUG_LOCKORDER (Matt Corallo)
0343676 Call TransactionRemovedFromMempool in the CScheduler thread (Matt Corallo)
a7d3936 Add a CValidationInterface::TransactionRemovedFromMempool (Matt Corallo)
Pull request description:
Based on #10179, this effectively reverts #9583, regaining most of the original speedups of #7946.
This concludes the work of #9725, #10178, and #10179.
See individual commit messages for more information.
Tree-SHA512: eead4809b0a75d1fb33b0765174ff52c972e45040635e38cf3686cef310859c1e6b3c00e7186cbd17374c6ae547bfbd6c1718fe36f26c76ba8a8b052d6ed7bc9
5ff01c236 [docs] Add instructions for lcov coverage report generation (James O'Beirne)
Pull request description:
After rediscovering the `lcov` report generation recipe one too many times, it seemed prudent to write some doc.
Tree-SHA512: 20e1b5f51ecd39e14bd67986a2c1578fb7da03a50625366eaca35b201db66aef99cd4a5456df3aaca5d2d66b18ed7d2e8eb8f3bd9c7aaf9af48164d9bac38931
7383d77 Updated instructions for Windows 10 Fall Creators Update. (Aaron Clauson)
e0fc4a7 Updated Windows build doc for WSL/Xenial workarounds. (Aaron Clauson)
Pull request description:
An update to the Windows build document that provides workarounds for the broken 64 bit mingw32 cross compiler on WSL/Xenial.
This update is an alternative to pull request #11437. While that pull request takes a valid approach by stating building on WSL should be avoided I think it is more useful to give Windows developers a workaround option.
The instructions have been tested on:
- Ubuntu 14.04 and 64 bit mingw32 tool chain
- Ubuntu 16.04 and 64 bit mingw32 tool chain
- Ubuntu 17.04 and 64 bit mingw32 tool chain
- Windows Subsystem for Linux (Windows 10 OS Build 15063.608) and 32 bit mingw32 tool chain
- Windows Subsystem for Linux (Windows 10 OS Build 15063.608) and 64 bit mingw32 tool chain
Related items:
- Serious incompatibility problems w/ newer mingw-64 on Ubuntu #8653
- `-fstack-protector-all` triggers crashes in mingw-w64 5.3.1 #8732
- Windows build appears broken on WSL (buntu okay) #10269
- Compilation error for windows target #11437
Tree-SHA512: 7c937e37ed7120ae5dcf61aba50e5228a7ed6f729647c724b8f48e7cbbd81366c1a83a818618766a8fe0418425e05ba2eba2b14f2616621c58606585444f45fc
659b206 Make listsinceblock refuse unknown block hash (Russell Yanofsky)
Pull request description:
Change suggested by @theuni who noticed listsinceblock would ignore invalid block hashes causing it to return a completely unfiltered list of transactions.
Tree-SHA512: 3c8fb160265780d1334e856e853ab48e2e18372b8f1fc71ae480c3f45317048cc1fee0055d5c58031981a91b9c2bdbeb8e49a889d04ecba61729ce8109f2ce3f
Change suggested by Cory Fields <cory-nospam-@coryfields.com> who noticed
listsinceblock would ignore invalid block hashes causing it to return a
completely unfiltered list of transactions.
0cd9273 rpc: Prevent `dumpwallet` from overwriting files (Wladimir J. van der Laan)
Pull request description:
Prevent arbitrary files from being overwritten by `dumpwallet`. There have been reports that users have overwritten wallet files this way. It may also avoid other security issues.
Fixes#9934. Adds mention to release notes and adds a test.
Tree-SHA512: 268c98636d40924d793b55a685a0b419bafd834ad369edaec08227ebe26ed4470ddea73008d1c4beb10ea445db1b0bb8e3546ba8fc2d1a411ebd4a0de8ce9120
Prevent arbitrary files from being overwritten. There have been reports
that users have overwritten wallet files this way. It may also avoid
other security issues.
Fixes#9934. Adds mention to release notes and adds a test.
This reduces the overhead in the git repo due to binary blobs of
the png files.
Also, the documentation can be updated independent of any tags and
release cycles.
204cc98 fix link error (Shooter)
Pull request description:
The `perform-gitian-builds` is not exist,
replace `perform-gitian-builds` with `setup-and-perform-gitian-builds`.
Tree-SHA512: c4f3fb4b6ae502a2e7a6857d3075734d493f549871b80ec00a2733ee689b00f98aa67ce7c3b7facf1ae4949b7845e1e2ef6f727aeca0c88c00b46d77b4d7e570
90ab62c45 [docs] document scripted-diff (John Newbery)
Pull request description:
Document scripted-diffs in developer-notes.md
I sometimes comment on PRs that a scripted-diff would be appropriate, but I don't have any documentation to point to. Fix that.
Tree-SHA512: 7d4a14b9217c812e4c27601e5e6dd8054cf5104cd20ecbe1ec0a84c217cc4b0645b7c0d2e3a89fdd4d059cafbc388acbddba75a430308f8279200b9383e009de
723aa1b qt: Backup former GUI settings on `-resetguisettings` (Wladimir J. van der Laan)
Pull request description:
Writes the GUI settings to `guisettings.bak` in the data directory before wiping them. This can be used to retroactively troubleshoot issues (e.g. #11262) where `-resetguisettings` solves the problem.
(as discussed in yesterday's IRC meeting)
Tree-SHA512: c64f5052d992eb02057ba285435f143c42d0cc456144a4c565e1c87be833737f9df750d0aee10810f85047c820d9b4f9f22fd94a6f09f4b28a9cf41b63a56586
Writes the GUI settings to `guisettings.bak` in the data directory
before wiping them. This can be used to retroactively troubleshoot
issues (e.g. #11262) where `-resetguisettings` solves the problem.
fa65dcd doc: Update release notes for 0.16.0 (MarcoFalke)
fa2c3b6 doc: Bump manpages to 0.15.99 (MarcoFalke)
Pull request description:
This updates the release notes for the breaking changes to `-usehd` option and the `getinfo` rpc.
Also, bumps the manpages to current master.
Tree-SHA512: 55b74375fa680d6043882e3cc37bc655840c9e719d67f60d4d615c10399d570cf6ed4dc338635be80d4044d4ed12cebde1370729ccb6794182e6d9c9910dab04
e91b96192 Create dependencies.md, and link dependencies file from README & build docs (flack)
Pull request description:
As @fanquake mentioned in #8639, this should probably be a file in `doc/`, so I went ahead and pulled the issue text via the github API and dumped it into a file. No modifications made, except one spelling fix. This makes the info easier to find, and it will get a proper version history, too.
Tree-SHA512: 6ba4c37c97200972a74724e0e346d6ad5947c01ad18638e15250f2b4cd747dd744aba16e306c98d59f35736542a5eded7a17b6a5ce6aebc63c0a9dc969b365ef
ce3baa193 changed regtest RPCport to 18443 to avoid conflict with testnet 18332 (Ferdinando M. Ametrano)
Pull request description:
using the same JSON-RPC default port for both testnet and regtest prevents running both at the same time on the same machine. Since RPCport=P2Pport-1 for both mainnet and testnet, and regtest P2Pport being 18444, 18443 is proposed for regtest RPCport
Documentation has been updated (or created where missing); manpages doc/man/bitcoin*.1 could include information for regtest too
Tree-SHA512: d42185f7ef54dc918ece19b543c8681d08bb9c5a971394e21f2d9a1091734b091b08df69fab622c207b46f402cf9323ded5b7a33fbd0af722388930169124e7f
python3 is required for running the unit tests on macOS, Ubuntu and Fedora.
Without python3 installed, 'make check' fails because /test/util/bitcoin-util-test.py fails to find python3.
f1708ef89 Add recommendation: By default, declare single-argument constructors `explicit` (practicalswift)
Pull request description:
This is a follow-up to the now merged #10969.
Add recommendation:
> By default, declare single-argument constructors `explicit`.
>
> - *Rationale*: This is a precaution to avoid unintended conversions that might arise when single-argument constructors are used as implicit conversion functions.
>
Tree-SHA512: 1ceb1008a7863ebd0f09ba9c06b4e28b3b03265d7381f9d0c8bd4be1663d5d0392de0ecd811027aa27c0d962723674b245b3c165a437942a776f3525db39d36b
fa14b67 [doc] build-windows: Mention that only trusty works (MarcoFalke)
Pull request description:
This should prevent people from running into the issues to later find that there is no solution yet.
Tree-SHA512: c0512bb15ebd62113a4195a9577fec4ddacf164509673e178c6b5445c16ab7b110a13ba829e6eebb2a66dff61eeac6ec77f7c5f60bd64685a0c0d99f71f4edf7
745d2e3 Clean up getbalance RPC parameter handling (Russell Yanofsky)
fd5d71e Update developer notes after params.size() cleanup (Russell Yanofsky)
e067673 Avoid treating null RPC arguments different from missing arguments (Russell Yanofsky)
e666efc Get rid of redundant RPC params.size() checks (Russell Yanofsky)
Pull request description:
This is a followup to #10783.
- The first commit doesn't change behavior at all, just simplifies code.
- The second commit just changes RPC methods to treat null arguments the same as missing arguments instead of throwing type errors.
- The third commit updates developer notes after the cleanup.
- The forth commit does some additional code cleanup in `getbalance`.
Followup changes that should happen in future PRs:
- [ ] Replace uses of `.isTrue()` with calls to `.get_bool()` so numbers, objects, and strings cause type errors instead of being interpreted as false. https://github.com/bitcoin/bitcoin/pull/11050#discussion_r133850525
- [ ] Add braces around if statements. https://github.com/bitcoin/bitcoin/pull/11050#discussion_r133851133
- [ ] Maybe improve UniValue type error exceptions and eliminate RPCTypeCheck and RPCTypeCheckArgument functions. https://github.com/bitcoin/bitcoin/pull/11050#discussion_r133829303
Tree-SHA512: e72f696011d20acc0778e996659e41f9426bffce387b29ff63bf59ad1163d5146761e4445b2b9b9e069a80596a57c7f4402b75a15d5d20f69f775ae558cf67e9
bea8e9e Document the preference of nullptr over NULL or (void*)0 (practicalswift)
Pull request description:
Document the preference of `nullptr` over `NULL` or `(void*)0`.
After this commit:
```
$ git grep "[^A-Za-z_]NULL[^A-Za-z_]" | grep -vE '(leveldb|univalue|secp256k1|torcontrol|NULL certificates|ctaes|release-notes|patches|configure.ac|developer-notes)'
$
```
Some context:
* `NULL → nullptr` was handled in the recently merged PR #10483
* `0 → nullptr` was handled in the recently merged PR #10645
Tree-SHA512: f863096aa4eb21705910f89713ca9cc0d83c6df2147e3d3530c3e1589b96f6c68de8755dcf37d8ce99ebda3cfb69805e00eab13bf65424aaf16170e9dda3958a
5be6e9b doc: Update build-openbsd for 6.1 (Wladimir J. van der Laan)
Pull request description:
- Bump "updated for"
- Fix link to boost (haenet mirror is broken)
- Upgrade boost version to 1.64
Ref: closes#10796
Tree-SHA512: 14d5e6a21c7079f5b16d763dd27abe6971c47b4ea2b563e10aafad52515d1d64abe395ecef6f2c00d41c1f852946831fb58737dcabf769b21a69b31d98727ad6
d201e40 Update init.md: Fix section numbering. (Carl Dong)
72a184a Update init.md: Fix line breaks in section 3b. (Carl Dong)
Pull request description:
Trivial commit that fixes Markdown line breaks in `docs/init.md`. Markdown line breaks take the form of two spaces, which is hard to spot when viewing raw text but visible when previewing on GitHub. Line 72-73 of `docs/init.md` did not conform to the rest the rest of the documentation, and is corrected in this PR.
Tree-SHA512: e5f048bd4e9e1e68372c95881f68b157a3c205d4dbcc6ccd24f2c0171b84d8cf7907d1835c6754ce57f35f9463820353ad7ae70c2e3de20136382ea3ee8bc4ff
1d8df0141 Fix MD formatting in REST-interface.md and spelling mistake in test_runner.py (MeshCollider)
41f3e84aa Fix inconsistencies and grammar in various files (MeshCollider)
Pull request description:
Just a simple fix of some inconsistent capitalization, formatting and grammar in a few files (no code changes)
Tree-SHA512: 60b12a5a5c69a1af4a25b7db0b32ed806ed62ad2966cee08b3792a7cfa7f51848fd485349b4c09e60a7eedfdf55ee730c51daa066d6e226ae404c93342bf3e13
f42fc1d50 doc: spelling fixes (klemens)
Pull request description:
patch contains some spelling fixes ( just in comments ) as found by a bot ( http://www.misfix.org, https://github.com/ka7/misspell_fixer ).
Tree-SHA512: ba6046cfcd81b0783420daae7d776be92dd7b85a593e212f8f1b4403aca9b1b6af12cef7080d4ea5ed4a14952fd25e4300109a59c414e08f5395cdb9947bb750
Now that 0.15 branch has been split off, master is 0.15.99 (pre-0.16).
Also clean out release notes.
Tree-SHA512: 160f712fae7bfc51e49e36a27ab01f5c243b79a19a70312df95f9bc5cb8067c70aa88911f741fd1625bee549a70655eaea24d98f6049d98c3c14ee1b3143f4cb
e93ff71 Add instructions for multi-processor gitian builds (Charlie Lee)
Pull request description:
This makes builds much faster if you have a multi-core machine.
Tree-SHA512: edb64c691a31a8a2e6c45f87886912d429a3fd600ebc0de2b16d44efd9d38bb92fea33c5fed207ad684b75d3247218912cab67661466a5538d534845e0808c9f
5a9b508 [trivial] Add end of namespace comments (practicalswift)
Tree-SHA512: 92b0fcae4d1d3f4da9e97569ae84ef2d6e09625a5815cd0e5f0eb6dd2ecba9852fa85c184c5ae9de5117050330ce995e9867b451fa8cd5512169025990541a2b
A few "a->an" and "an->a".
"Shows, if the supplied default SOCKS5 proxy" -> "Shows if the supplied default SOCKS5 proxy". Change made on 3 occurrences.
"without fully understanding the ramification of a command" -> "without fully understanding the ramifications of a command".
Removed duplicate words such as "the the".
589827975 scripted-diff: various renames for per-utxo consistency (Pieter Wuille)
a5e02bc7f Increase travis unit test timeout (Pieter Wuille)
73de2c1ff Rename CCoinsCacheEntry::coins to coin (Pieter Wuille)
119e552f7 Merge CCoinsViewCache's GetOutputFor and AccessCoin (Pieter Wuille)
580b02309 [MOVEONLY] Move old CCoins class to txdb.cpp (Pieter Wuille)
8b25d2c0c Upgrade from per-tx database to per-txout (Pieter Wuille)
b2af357f3 Reduce reserved memory space for flushing (Pieter Wuille)
41aa5b79a Pack Coin more tightly (Pieter Wuille)
97072d668 Remove unused CCoins methods (Pieter Wuille)
ce23efaa5 Extend coins_tests (Pieter Wuille)
508307968 Switch CCoinsView and chainstate db from per-txid to per-txout (Pieter Wuille)
4ec0d9e79 Refactor GetUTXOStats in preparation for per-COutPoint iteration (Pieter Wuille)
13870b56f Replace CCoins-based CTxMemPool::pruneSpent with isSpent (Pieter Wuille)
05293f3cb Remove ModifyCoins/ModifyNewCoins (Pieter Wuille)
961e48397 Switch tests from ModifyCoins to AddCoin/SpendCoin (Pieter Wuille)
8b3868c1b Switch CScriptCheck to use Coin instead of CCoins (Pieter Wuille)
c87b957a3 Only pass things committed to by tx's witness hash to CScriptCheck (Matt Corallo)
f68cdfe92 Switch from per-tx to per-txout CCoinsViewCache methods in some places (Pieter Wuille)
000391132 Introduce new per-txout CCoinsViewCache functions (Pieter Wuille)
bd83111a0 Optimization: Coin&& to ApplyTxInUndo (Pieter Wuille)
cb2c7fdac Replace CTxInUndo with Coin (Pieter Wuille)
422634e2f Introduce Coin, a single unspent output (Pieter Wuille)
7d991b55d Store/allow tx metadata in all undo records (Pieter Wuille)
c3aa0c119 Report on-disk size in gettxoutsetinfo (Pieter Wuille)
d34242430 Remove/ignore tx version in utxo and undo (Pieter Wuille)
7e0032290 Add specialization of SipHash for 256 + 32 bit data (Pieter Wuille)
e484652fc Introduce CHashVerifier to hash read data (Pieter Wuille)
f54580e7e error() in disconnect for disk corruption, not inconsistency (Pieter Wuille)
e66dbde6d Add SizeEstimate to CDBBatch (Pieter Wuille)
Tree-SHA512: ce1fb1e40c77d38915cd02189fab7a8b125c7f44d425c85579d872c3bede3a437760997907c99d7b3017ced1c2de54b2ac7223d99d83a6658fe5ef61edef1de3
This makes the following changes:
* In undo data and the chainstate database, the transaction nVersion
field is removed from the data structures, always written as 0, and
ignored when reading.
* The definition of hash_serialized in gettxoutsetinfo is changed to no
longer incude the nVersion field. It is renamed to hash_serialized_2
to avoid confusion. The new definition also includes transaction
height and coinbase information, as this information was missing
before.
This depends on having a CHashVerifier-based undo data checksum
verifier.
Apart from changing the definition of serialized_hash, downgrading
after using this patch is supported, as no release ever used the value
of nVersion field in UTXO entries.
661caf8 [doc] Minor corrections to osx dependencies (fanquake)
Tree-SHA512: 61451807d6208002550d2e37d26094a5515b11daacab39eb508b6168eebcea86f93dcc7f853aab490baec3727740c90d404c481e11b3d03dcea9f76f8fc7be12
41b8821 Add updating of chainTxData to release process (Pieter Wuille)
Tree-SHA512: f7d6e72b19aa83fc4851a9316d6c6a236e0e914d637525cda42c0b15a94543b8072ce67b57d6b12141332a03b64b6c715dff4d61e6e58e0197b22305b35ad65d
09fe2d9 release: update docs to show basic codesigning procedure (Cory Fields)
f642753 release: create a bundle for the new signing script (Cory Fields)
0068361 release: add win detached sig creator and our cert chain (Cory Fields)
Tree-SHA512: 032ad84697c70faaf857b9187f548282722cffca95d658e36413dc048ff02d9183253373254ffcc1158afb71140753f35abfc9fc8781ea5329c04d13c98759c0
8c156b7 Bugfix: Only install manpages for built programs (Luke Dashjr)
Tree-SHA512: f4c40910b257274a05d9c842b9adb5d9d01df7dd2d34a18bd2d98c78810dc3ed98ed12c08c55352e36a845f06ddb1efba9d4ecf5f1123d2c58406a5ecf589836
The big notice at the top of the release note is not interesting
to most users now and apparently comes across poorly to some.
Better to provide more information about what we do support.
This disentangles the script validation skipping from checkpoints.
A new option is introduced "assumevalid" which specifies a block whos
ancestors we assume all have valid scriptsigs and so we do not check
them when they are also burried under the best header by two weeks
worth of work.
Unlike checkpoints this has no influence on consensus unless you set
it to a block with an invalid history. Because of this it can be
easily be updated without risk of influencing the network consensus.
This results in a massive IBD speedup.
This approach was independently recommended by Peter Todd and Luke-Jr
since POW based signature skipping (see PR#9180) does not have the
verifiable properties of a specific hash and may create bad incentives.
The downside is that, like checkpoints, the defaults bitrot and older
releases will sync slower. On the plus side users can provide their
own value here, and if they set it to something crazy all that will
happen is more time will be spend validating signatures.
Checkblocks and checklevel are also moved to the hidden debug options:
Especially now that checkblocks has a low default there is little need
to change these settings, and users frequently misunderstand them as
influencing security or IBD speed. By hiding them we offset the
space added by this new option.
2fb98f6 Fix bug in dmg builder so that it actually reads in the configuration file (Don Patterson)
b01667c Mention RSVG dependency when creating the disk image on OSX (Jonas Schnelli)
09aefb5 build: Fix 'make deploy' for OSX (Cory Fields)
I did a build on a windows 10 laptop and took notes, and tried
to improve the document:
- It's the Linux subsystem for Windows, not the other way around.
- Split out dependencies: general ones, 64-bit, 32-bit. Remove the
reference to `build-unix.md`, easy enough to be self-contained.
- Place 64-bit instructions first. 99% will want these.
- Installation instructions: recommend using `/` for prefix, same as we
do on gitian builds. This will allow copying the files to a usable
(from Windows) place using just `make DESTDIR=...`.
- Remove double spaces / consistent width reformatting.
Refer to the right file in the top-level README.md.
Having only one file with test documentation saves some confusion about
where things are documented.
This introduces a 'minimum chain work' chainparam which is intended
to be the known amount of work in the chain for the network at the
time of software release. If you don't have this much work, you're
not yet caught up.
This is used instead of the count of blocks test from checkpoints.
This criteria is trivial to keep updated as there is no element of
subjectivity, trust, or position dependence to it. It is also a more
reliable metric of sync status than a block count.
> This new feature is enabled by default if Bitcoin Core is listening, and a connection to Tor can be made. It can be configured with the -listenonion, -torcontrol and -torpassword settings. To show verbose debugging information, pass -debug=tor.
But it is correct to say that the feature is enabled *regardless* of whether a connection to Tor can be made.
I propose to clarify that so that users can eliminate these in their logs (when `listen=1` and no Tor).
And I think it's okay to clarify about the `listen` option, because on several occasions when I read this before I always assumed `listening` meant `server=1` which cost me a lot of time in troubleshooting.
```
2016-10-24 06:19:22.551029 tor: Error connecting to Tor control socket
2016-10-24 06:19:22.551700 tor: Not connected to Tor control port 127.0.0.1:9051, trying to reconnect
```
### What version of bitcoin-core are you using?
0.12.1
The new Windows Subsystem for Linux (WSL) allows a user to run a bash shell directly on Windows in an Ubuntu based environment. This can be used to cross-compile Bitcoin directly on Windows without the need for a separate Linux VM or Server. The instructions included in this commit explain how to configure the environment and build Bitcoin Core using this new feature.
* Minor formatting such as adjusting links
* Move sections of `doc/multiwallet-qt.md` to the source code and delete
the file, as it is outdated
* Fix typo in the release notes
* Amend release process to mention update of BLOCK_CHAIN_SIZE
- Changed Debian 8.5.0 ISO CD ROM URL by redirecting from current (which now has only 8.6.0) to a persistent archive link which should not change anytime soon.
- Added a link to official Debian checksum verification procedure (which is more verbose and also acts as a backup source of SHA256sum's)
- Fix capitalization (iso)
d19583f improved gen-manpages.sh, includes bitcoin-tx and strips commit tag, now also runs binaries from build dir by default, added variables for more control (nomnombtc)
09546ca regenerated all manpages with commit tag stripped, also add bitcoin-tx (nomnombtc)
ae6e754 change help string --enable-man to --disable-man (nomnombtc)
a32c102 add conditional for --enable-man, default is yes (nomnombtc)
dc84b6f add doc/man to subdir if configure flag --enable-man is set (nomnombtc)
00dba72 add doc/man/Makefile.am to include manpages (nomnombtc)
eb5643b add autogenerated manpages by help2man (nomnombtc)
6edf2fd add gen-manpages.sh description to README.md (nomnombtc)
d2cd9c0 add script to generate manpages with help2man (nomnombtc)
- Python 3 now supported.
- Bump boost version to 1.61 - one boost patch no longer needed.
- All checked with OpenBSD 5.9, except for the clang part, I left this
as-is for someone adventurous.
- Mention overriding resource limits, OpenBSD's default ulimit does not
suffice for building Bitcoin Core with gcc 4.9.3.
