viperproject/gobra

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Gobra is an automated, modular verifier for Go programs, based on the Viper verification infrastructure.

Stars: 189
Forks: 45
Open beginner issues: 0
Indexed issues: 163
Avg merge: 2d 23h
Merged PRs (30d): 4

Dominant language: Scala
License: No license data
Last GitHub push: Sep 8, 2026
Latest indexed: Sep 20, 2026
Contributing guide: No contributing guide
Code of conduct: No code of conduct
Beginner labels: No beginner labels indexed

Beginner friendly Everything

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163 open issues indexed

Termination measures are not checked for closure spec calls Open

soundness termination-checking

Difficulty 4/5 3-5 days Newbie friendliness 48/100

viperproject/gobra#1106 · Opened Sep 4, 2026
Termination measures of interface methods are not checked across package boundaries Open

soundness termination-checking

Difficulty 5/5 Over a week Newbie friendliness 30/100

viperproject/gobra#1105 · Opened Sep 4, 2026
Type checker crashes on addressing an element of a slice obtained from a map lookup Open

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

viperproject/gobra#1097 · Opened Aug 17, 2026
Tutorial.md is severely limited compared to actual *.g4 files Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#1093 · Opened Aug 15, 2026
Quantified predicate permission over freshly-allocated pointers fails injectivity check, even for provably-fresh allocations Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#1060 · Opened Jul 31, 2026
Pure interface method's definitional axiom does not fire through interface dispatch when the method recurses through another interface-typed call Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

viperproject/gobra#1059 · Opened Jul 30, 2026
Cannot prove non-nil after make Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#1052 · 2 comments · Opened Jul 19, 2026
It is unnecessarily hard to prove injectivity of slices of struct pointers Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#1051 · Opened Jul 18, 2026
Proposed annotation: verified — heap-free function postconditions as domain axioms Open

encoding enhancement syntax

Difficulty 5/5 Over a week Newbie friendliness 35/100

viperproject/gobra#1037 · 9 comments · Opened Jun 14, 2026
Invalid Triggers via Subslicing Open

bug encoding invalid triggers

Difficulty 4/5 3-5 days Newbie friendliness 42/100

viperproject/gobra#1030 · 1 comment · Opened May 13, 2026
Gobra does not immediately realize semantics of copying arrays by assignment Open

bug encoding incompleteness

Difficulty 3/5 1-2 days Newbie friendliness 48/100

viperproject/gobra#1027 · 6 comments · Opened May 6, 2026
Can prove nil-ness and non-nilness from struct predicate Open

documentation

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#1025 · 5 comments · Opened May 4, 2026
Incomplete Slice Allocation Spec Open

encoding enhancement

Difficulty 3/5 1-2 days Newbie friendliness 52/100

viperproject/gobra#1007 · Opened Mar 4, 2026
Parser Error for Reserved Keywords Open

enhancement parsing

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#1005 · Opened Mar 2, 2026
Allow impure assertions for `assert by` Open

feature-request

Difficulty 3/5 1-2 days Newbie friendliness 38/100

viperproject/gobra#999 · Opened Feb 24, 2026
Invalid SMT Encoding Open

bug encoding

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#997 · Opened Feb 20, 2026
Unintuitive semantics for mixed non-hyper-predicates and hyper-predicates Open

documentation SIF

Difficulty 5/5 Over a week Newbie friendliness 30/100

viperproject/gobra#996 · 10 comments · Opened Feb 17, 2026
Using `rel(t,0) < rel(t,1)` with implication in SIF mode causes an error. Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 32/100

viperproject/gobra#994 · 2 comments · Opened Feb 11, 2026
Assert might fail even defined before the `ghost if ` block in hypermode using `rel()` Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#993 · 3 comments · Opened Feb 6, 2026
Cross execution access bug in `rel()` and `ghost if` blocks Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#992 · 2 comments · Opened Feb 4, 2026
Encoding bug when using `rel()` and a wrapper Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#987 · 1 comment · Opened Jan 27, 2026
Floating Point Literals Open

encoding enhancement

Difficulty 5/5 Over a week Newbie friendliness 30/100

viperproject/gobra#980 · 1 comment · Opened Dec 10, 2025
Crash when using a compound data structure in a closure encoding Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#978 · Opened Dec 3, 2025
Confusing error message if ADT type and constructor named alike Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#977 · Opened Dec 3, 2025
`fix-846`: "type checking" that `low` may only occur in the contracts of `pure` functions that are marked as `hyper` does not extend to interface definitions Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#974 · Opened Oct 7, 2025
Exception when type conversion is missing its argument Open

type checking

Difficulty 3/5 1-2 days Newbie friendliness 48/100

viperproject/gobra#972 · Opened Sep 27, 2025
Incompleteness in proving equality of strings Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#966 · Opened Aug 29, 2025
`fix-846`: An imported non-`ghost` `hyper` function is not considered `hyper` Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#965 · 2 comments · Opened Aug 20, 2025
`fix-846`: Need relational operator to refer to value in specific program execution Open

SIF

Difficulty 5/5 Over a week Newbie friendliness 35/100

viperproject/gobra#963 · 1 comment · Opened Aug 18, 2025
`fix-846`: Gobra crashes when trying to return the value of a field from a `hyper` function Open

error reporting SIF

Difficulty 3/5 1-2 days Newbie friendliness 38/100

viperproject/gobra#962 · Opened Aug 18, 2025
Gobra crashes when defining an interface with a predicate and embedding another interface without that predicate Open

Difficulty 3/5 1-2 days Newbie friendliness 50/100

viperproject/gobra#959 · Opened Aug 13, 2025
Gobra crashes on ghost comparison of interface instances where one interface embeds the other Open

Difficulty 4/5 3-5 days Newbie friendliness 55/100

viperproject/gobra#958 · Opened Aug 13, 2025
Example of unstable verification (with `--hyperMode=on`) Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 25/100

viperproject/gobra#957 · Opened Aug 13, 2025
Neat trick for mutual recursion impossible Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#956 · 3 comments · Opened Aug 10, 2025
`fix-846`: Viper encoding leads to insufficient permissions with interfaces Open

highpriority

Difficulty 4/5 3-5 days Newbie friendliness 25/100

viperproject/gobra#955 · 2 comments · Opened Aug 8, 2025
(hyper)Gobra crashes when implementing interface containing a terminating function (`decreases`) with a predicate containing `low(...)` (`--hyperMode=on`) Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#949 · Opened Jul 25, 2025
`decreases` in interface introduces non-low branch condition (`--hyperMode=on`) Open

SIF

Difficulty 5/5 Over a week Newbie friendliness 25/100

viperproject/gobra#948 · 3 comments · Opened Jul 18, 2025
Incorrect encoding of magic wand package statement with `--hyperGobra=on` and `--hyperGobra=extended` Open

SIF

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#946 · Opened Jul 17, 2025
Gobra crashes on implementation proof for `(*T)` when `T` implements `pure` interface method Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

viperproject/gobra#939 · Opened Jun 26, 2025
Unsound implementation proof for `(*T)` when interface method is implemented on `T` Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#938 · 1 comment · Opened Jun 26, 2025
Casting to a map does not allow for ok flag to be checked Open

Difficulty 4/5 3-5 days Newbie friendliness 42/100

viperproject/gobra#936 · 4 reactions · Opened Jun 19, 2025
Gobra's append is unable to preserve invariant Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

viperproject/gobra#935 · 4 reactions · Opened Jun 19, 2025
for-range: 0 <= i cannot be proven without len(x) > 0 Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

viperproject/gobra#934 · 1 comment · 4 reactions · Opened Jun 15, 2025
Cannot check if type is []map[string]interface{} Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#932 · 1 reaction · Opened Jun 6, 2025
Converting array behind pointer to slice using type definition crashes Gobra Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

viperproject/gobra#931 · 1 comment · 2 reactions · Opened Jun 4, 2025
Unable to prove assert directly after equivalent assume Open

mapencoding

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#930 · 3 comments · 1 reaction · Opened Jun 4, 2025
Adding slice to map removes permissions of other slices in map Open

mapencoding

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#929 · 6 comments · 2 reactions · Opened Jun 3, 2025
Identity comparison with other slices fails after appending to slice Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

viperproject/gobra#928 · Opened Jun 3, 2025
Gobra reports reveal parser error if there is a parser error somewhere else Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

viperproject/gobra#924 · 2 comments · 2 reactions · Opened May 13, 2025
`ghost` annotation is not always required in declaration of variables of ghost type Open

type checking

Difficulty 4/5 3-5 days Newbie friendliness 42/100

viperproject/gobra#922 · 2 comments · Opened May 9, 2025

viperproject/gobra

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